The repair and fitting of Atlas lathes is the primary subject of this file but many practices discussed here might be useful for other brands. There are some repair discussions about the nuts involved for threading, half-nuts or split-nuts (hyphen optional), in the text file on this site called "Thread Dial and Half Nuts". Also, there are discussions in the text file "Atlas Parts General" as to how some parts may be repaired or even made from scratch. I hope that Atlas owners will learn to read as well as think outside the box. The perfect solution to your Atlas lathe's problem might be completely solved in another group devoted to Taig or Sherline or Myford or Logan or South Bend or 7 X 10...12...whatever Minilathes or ......., and v.v. For example, a very useful message on the Subject: Lathe Alignment Technique appeared in the mlathemodsx~xxyahoogroups.com on 31 Jan 2004. Great advice as to how to make your headstock and tailstock align. That message appears in this file now because it is applicable to any lathe brand. There are a (very) few hints here for problems with Sears' 109 (not Atlas). Those users will do well to join a 109 related group to seek and share ideas. If you got to this file directly from my HOME PAGE, return there by using your browser's back button. BUT if you came to this file as the result of a web search engine, see more than 70 additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/ SAFETY WARNING BEWARE: DO NOT ASSUME that any subject matter or procedure or process is safe or correct or appropriate just because it was mentioned in a news/ user group or was included in these files or on this site or on any other web site or was published in a magazine or book or video. Working with metals and machinery and chemicals and electrical equipment is inherently dangerous. Wear safety devices and clothing as appropriate. Remove watches, rings, and jewellery -- and secure or remove loose clothing -- before operating any machine. Read, understand and follow the latest operating procedures and safety instructions provided by the manufacturer of your machine or tool or product. If you do not have those most recent official instructions, acquire a copy through the manufacturer before operating or using their product. Where the company no longer exists, use the appropriate news or user group to locate an official copy. Be careful -- original instructions may not meet current safety standards. Updated safety information and operating instructions may also be available through a local club, a local professional in the trade, a local business, or an appropriate government agency. In every case, use your common sense before beginning or taking the next step; and do not proceed if you have any questions or doubts about any procedure, or the safety of any procedure. Follow all laws and codes, and employ certified or licenced professionals as required by those laws or codes. Hazardous tasks beyond your competence or expertise should also be contracted to professionals. Let's be really careful out there. (c) Copyright 2003 - 2008 Machining and Metalworking at Home The form of the collected work in this text file (including editing, additions, and notes) is copyrighted and this file is not to be reproduced by any means, including electronic, without written permission except for strictly personal use. ======================================================================== From: Jon Elson Date: Tue Jun 20, 2000 4:58pm Subject: Re: bed regrind "M K Campbell Jr." wrote: > I have a Craftsman 12x36 that the bed was in really bad > shape. The ways had worn badly and had many dings through > the whole length of the bed like they used it for an anvil > for years. If I adjusted the gibs for snug fit close to the > head stock, I could get only about 12" travel before > binding. I didn't think the lathe was worth regrinding (and > couldn't afford it either). I found a grinding shop, > Southwest Grinding in Ft Worth, TX, that does not have a > surface grinder but the guy told me he had done several flat > bed lathes on his Blanchard grinder. He put the lathe bed on > the grinder mag chuck upside down and topped the mounting > surfaces so they were parallel with the bed surface. Then > flipped it over and took a few thousandths off the top, just > enough to remove the groove worn by the carriage. It made a > great improvement. I had to mill a little off the front gib > to get it to take up the slack. > Cost of the grinding, $32.00. If I could figure a way to grind the > bottom of the rear way, it would be even better. I know this isn't > the best solution but it's still a lot better than it was. Wow, that's cheap! What I was thinking, about grinding the underside of the ways, was to build a little guide block that would ride on the top part of the bed. It would wrap around the bed way, and hold a grinder (Dremel, air die grinder, etc.) with an adjustable mount, so it could be brought up in tiny increments until it removes the low spot. This could be moved by hand to grind the bottom parallel to the top. Jon ------- From: gcontreras Date: Tue Jun 20, 2000 6:53pm Subject: Re: bed regrind Some time ago, I too was faced with this "resurfacing" problem on my just bought Atlas 3990. I did the same thing; had the bed reground by an automotive repair shop (does big diesel engine repairs). The guy first setup several high T rests and surfaced the top of these. This would assure that the lathe bed would sit on a true surface. The bed was held on these T rests from the underside of the lathe bed (way) proper as it had little or not wear at all as the feet had been removed. The result was just about right. I then laped the bed with a home made 40" straight edge (2" x 5"). What you want is to have all the surfaces parallel and square to each other. When I first placed the carriage on the bed I could barely remove it as it seemed to have stuck it self to the bed surface! The bed was that flat. I have just completed the paint work and have taken my first cut after leveling. No problem at all! A straight cut, no strange markings (rings) and no binding across the entire bed. Well worth it Jim as my lathe a 0.5mm groove on the front shear running towards the headstock and I feel I'm better off... Cost? about $60.00. ------- From: Jon Elson Date: Tue Jun 20, 2000 7:56pm Subject: Re: Re: bed regrind,bottom Pete & Sheri wrote: > I wonder how much wear actually occurs on the "bottom" surfaces. I had a > 10-54 years ago that had lots of wear on the top of the rails, but that > wear was from the carriage running back and forth. The wear on the rear > side would have been from the bed resisting the tool, I assume. But > I wonder if the forces on the underside of the bed would create enough > wear to worry about. Has anybody had a bed reground who knows what had > to be taken off of the "bottom" in order to true it up? Unless the gibs on the bottom were set VERY tight, or there was a lot of swarf getting under there (which is a possibility), there should be VERY little wear. But, when the top of the bed is reground, it is unlikely that the bottom edge is still totally parallel to the top. That's what matters. So, if the grinding ended up taking a little more off one end than the other, the vertical thickness of the ways will now have a 'taper' from one end to the other. That would make setting the bottom gib shims rather tricky, and leave it loose at one end. Strong tool infeed pressure will lift the back of the carriage if the bottom gibs are not fairly snug. This is a problem when parting-off, for instance, also with threading. Jon ------ From: Walter E Emery Date: Wed Jun 21, 2000 7:32pm Subject: Re: bed regrind Blanchard grinding is done with a large diameter ring stone with the part to be ground on a rotating magnetic table, usually with pretty coarse grit stones and flooding coolant. I had one in my shop for many years, but would never use it for lathe beds. Its main purpose is rapid removal of stock. While a Blanchard is usually sufficient for automotive cylinder heads which will sit stationary on a gasket, I certainly wouldn't want my lathe bed ground that way, as it will leave swirl marks across the ways which will not be conducive to even wear or smooth operation. A big surface grinder is required with a skilled operator to do the job properly. Even a few thousandths of taper can really screw up the operation of your lathe, and as Earl said, the guy must know what wheels to use. Walt Emery -------- From: Guy Fuller Date: Mon Jun 26, 2000 8:23pm Subject: Re: re: bed regrind >>Mickey, For a novice would you please expound a little on hand scraping. > Ouch! That's not an easy subject. But, historically, the accuracy of > machine tools was assured not by grinding the bed on a huge surface > grinder, but by a guy with a small hand tool and a big straightedge. > > The general way this is done is you apply some blue painter's pigment > (Prussian Blue) to either the object or the straightedge (surface plate, > precision square, etc.) and then rub the two together. By examining > the pattern left on the part, you can see how accurately it fits against > the master. When it gets quite close, you can start tweaking how many > microscopic high spots per square inch there are. These high spots > are called bearing points. Supposedly, you are supposed to go for > about 25 bearing points per square inch. > > How this is done is that the pattern of the bluing tells you where the > high spots are, and you use the scraping tool to scrape off tiny > slivers of iron until the high spots are reduced. Then, you check > against the straight edge again. > > There is a LOT of technique to this. I have done some small experiments > with it, and found it does work, and can be done without vast > amounts of skill. I suspect the skill comes in when planning how > to perform spotting and scraping on larger pieces, where you can > quickly get in a mess while working on one area, such that another > area is totally off. I have a well worn Bridgeport that really needs > a good scraping job done on it. Jon ------- Date: Wed, 20 Sep 2000 11:37:07 EDT From: catboat15x~xxaol.com Subject: Re: New to the list In a message dated 9/19/00, fbcwinx~xx3g.quik.com writes: << Here's a quick question: The cross slide seems to have quite a bit of play in it. Any suggestions on how to shore it up for facing turns? >> Look along the right side of the cross slide. There should be some small headless screws with thin lock nuts there. These adjust the gib (or jib) which is a piece that bears against the side of dovetail where the cross slide moves. Using a thin wrench loosen the lock nuts a bit, use a screwdriver to tighten the screws till you feel the cross slide is locked then loosen just enough to let it move. Kind of a tedious project to get all the adjustment screws set, then locked so the cross slide moves easily with no shake. You, (or at least I do) have to have wrench in one hand, screwdriver in other But, a normal part of using a lathe. John Meacham ------- Date: Wed, 20 Sep 2000 08:55:48 -0700 From: "Robert Streimikes" Subject: Re: New to the list From: "Harry Boyd" > My trouble is not that the gib screws are loose. I can tighten them down > fully, and the whole cross slide will still vibrate. Any ideas? If you have tightened both sets of gibs (cross slide and compound) and still have the problem then perhaps the saddle is what is vibrating? If so the relevant adjustments are underneath the saddle and there have been a bunch of posts in the past on how to deal with it (esp on what to do after you break the cheezy cast iron gibs (or what ever they are called) down there.) Regards Bob ------- Date: Wed, 20 Sep 2000 12:03:42 -0400 From: Jude Miller Subject: Re: New to the list >My trouble is not that the gib screws are loose. I can tighten them down >fully, and the whole cross slide will still vibrate. Any ideas? Harry Do you mean that the carriage vibrates? The carriage is the piece that slides on the bed of the lathe. The cross slide slides in and out on the carriage. The carriage has a gib on the back, I believe. There are also adjusting shims underneath the carriage to take up slop in the vertical direction. Older lathe beds often have sufficient wear that the carriage must be somewhat loose at a normal working distance from the headstock in order to traverse the rest of the bed at all. This can be fixed by grinding or scraping, but this is not a minor procedure. Best, Jude Miller ------- Date: Wed, 20 Sep 2000 15:44:08 EDT From: catboat15x~xxaol.com Subject: Re: New to the list In a message dated 9/20/00, fbcwinx~xx3g.quik.com writes: << My trouble is not that the gib screws are loose. I can tighten them down fully, and the whole cross slide will still vibrate. Any ideas? >> Hi Harry: Are you sure there is a gib in there? Also make sure you loosen the lock nuts enough since I have had the locknuts "lock up" before I got full travel on the adjustment screws. Otherwise, if everything is tight and snug, maybe you are taking too large a bite out of your work. One thing to look for is the difference between plain turning and facing. When you are working on a round piece to reduce diameter there is some clearance for the front of the tool due to the geometry of the set up. (Visualize a flat ended tool against a clyinder and there is front clearance just because the work piece is round.) When facing it is much easier for the "heel" of the tool to drag on the work. If all else fails try to regrind your tool bit to give more clearance to the front end. John Meacham ------- Date: Wed, 20 Sep 2000 15:32:58 -0500 From: Jon Elson Subject: Re: loose cross slide? > In a message dated 9/20/00, fbcwinx~xx3g.quik.com writes: > << My trouble is not that the gib screws are loose. I can tighten them > down fully, and the whole cross slide will still vibrate. Any ideas? >> Well, there has to be something loose! There are a number of possibilities. There is a gib on the back of the carriage, and two gibs on the UNDERSIDE of the carriage. These are two steel (or cast iron?) plates, with laminated aluminum shims underneath. On several Atlas lathes that had been 'buggered', the laminated shims were turned into accordion pleats, making the gib very loose. This allows the carriage to lift up off the bed with heavy infeed force. You tighten these gibs up by peeling a laminated strip, one at a time. There is also a gib on the carriage, and one on the compound slide. The compound slide tends to get loose, as it is a lightly constructed piece. Finally, there is a swivel that the lower part of the compound slide rests on. There can be problems that cause the swivel to not bear weight properly, so that it wobbles. On a light lathe like the Atlas, you should be able to apply forces with your hand to make the loose junction shift. Without the spindle running, you can get your head right in there to see what is moving. Once you determine exactly what part is shifting, you will know where to look for the problem. Finally, leadscrew backlash might be the problem. If so, then you definitely have some kind of problem with the cutting tool shape or the way you are holding it, as it is developing too much side force on the facing cuts. One last (awful) possibility is that the cross slide casting has cracked, and all it needs is a little more deflection, and it will split into two big pieces! I sure hope this is not what is happening. Jon ------- Date: Wed, 20 Sep 2000 22:55:59 -0500 From: "M K Campbell Jr." Subject: Re: Leadscrews I talked to Nolan Supply last year about Acme rod 3/4 x 8tpi. They don't list it in their catalog, only 6 and 10 tpi, but they custom make just about anything you want. The guy told me they could make a 6 ft. stick for me for around 50.00 if I remember right. I ended up finding a replacement for my 12x36 so I didn't ever order it. Nolan is at 800-736-2204 or www.nolansupply.com Skip Campbell Ft. Worth, Texas mkctools.com Craftsman 101.28990 12x36 ------- Date: Mon, 25 Sep 2000 21:23:51 -0500 From: "J Tiers" Subject: Re: Green Model 109.2127 The green color probably indicates a re-paint job, that's all, I think they were blue to start with in newer models. No parts are available, almost, except for used, or whatever M Herman has. He adverts in Home Shop Machinist magazine in the classifieds. A guy in Arizona also is supposed to have parts, but he seems to run hot and cold as the mood takes him. Anyhow, I have heard of doing the JB weld trick, but using a material that was described as "titanium putty". Seems like JB with a better binder and different filler metal. Done by professional rebuilders, on halfnuts yet. You can try JB, or get the other stuff from J&L Industrial etc, etc. ($$$) maybe some clean cast iron filings mixed in would stiffen JB up a bit, I tried it on another item and it seemed to work. Grease up the leadscrew and clean the halfnut lever like crazy before you do it. You might even try boiling it in water for a while, as the cast iron soaks up oil deep in the pores and that is poison to adhesives. Chatter is the big issue with the 109 because it is so light built. A follower rest is perfect. There are plans for one in the AAdocs 2 file in the metalworking dropbox, which I forget right now how to get to. Clamps onto the crosslide ways to hold it. Oil the daylights out of the rest fingers and it won't be too bad. And the smoother the fingers are the less they mark the surface. $100 is the right type of price, its what I paid, and I got a faceplate but no chuck. Hey, some people have paid up to $500 for the same thing. Jerry ------- Date: Tue, 26 Sep 2000 10:30:22 EDT From: ccnn51x~xxaol.com Subject: Re: Green Model 109.2127 In a message dated 9/25/00, jtiersx~xxworldinter.net writes: < Anyhow, I have heard of doing the JB weld trick, but using a material that was described as "titanium putty". Seems like JB with a better binder and different filler metal. Done by professional rebuilders, on halfnuts yet. You can try JB, or get the other stuff from J&L Industrial etc, etc. ($$$) maybe some clean cast iron filings mixed in would stiffen JB up a bit, I tried it on another item and it seemed to work. Grease up the leadscrew and clean the halfnut lever like crazy before you do it. You might even try boiling it in water for a while, as the cast iron soaks up oil deep in the pores and that is poison to adhesives.>> Iron filings mixed with JB Weld? Might work. Need to be clean alright; not from around a grinding wheel. Maybe from use of a real fine file. I wouldn't use grease on the leadscrew; wipe really good and then wipe really well with wax paper. Grease can contaminate the JB. Yes, boil the halfnut with a little acid cleaner. But are you sure this is necessary? If you use a spring weight scale on the close lever for the halfnuts and apply an extra 2 pounds after it is closed, will it be tight on the leadscrew? If so the problem may be the spring and ball bearing. Often they are worn and the spring is not strong enough. To replace, open the halfnuts, and take off the handwheel on the right end of the leadscrew. File off the burr from the setscrew and push the leadscrew to the left. Loosen the four front screws for the front gibbs and remove the back gibb from the carriage. Lift off the carriage. When you flip the lever for the halfnuts the other way the ballbearing and spring will fire out so have it pointed down in a big plastic pail. Get a new ballbearing and spring (stiffer than before) that just enter the hole (got mine from ACE Hardware). Make sure the spring is ground flat at the ends and remove any sharp edges. Clark Nicholas ------- Date: Wed, 11 Oct 2000 02:39:08 -0000 From: "Steven Christmann" Subject: Re: Carriage Clearance Hi Dale: Actually, I didn't pay a dime for my regrind (I called in a favor from a supplier at work). If I were to buy this service, however, it shouldn't be more than $25 for a top grind, and another $10-$15 to 'dust' the positive edge for squareness. Careful though - the ways on these lathes are thin to start with - you wouldn't want to remove much more than .005"-.010" If you need, I can give you numbers for several good grind houses in the Detroit area. I noticed that mine (which had taken to sagging in the middle from carriage weight and an improper stand) runs very true now - about .0003" max flat and coplanar across the entire bed length. It might also help if you regrind the bottom mating surface of the headstock parallel to the bearing bores, and the bottom surface of the tailstock - this way you won't experience any runout later on. I also set my headstock-tailstock on a surface plate and set the heights together. If you want, I can e-mail you the drawings for a jig that I made up to hold the headstock upside down for grinding. I think Atlas did a pretty sloppy fitting job on these lathes originally. Hope that helps, Steve ------- Date: Sat, 18 Nov 2000 08:36:14 -0600 (CST) From: dswrx~xxwebtv.net Subject: Leveling a lathe... The 'Lathe Bulletin 101.07-3" discusses the reasons and methods of leveling a lathe bed. Leveling, according to the bulletin means; The bed ways must be parallel with themselves. Absolutely level bed is essential for accurate lathe work. The bulletin warns that a twisted bed is also harmful to the lathe. The best way to do this is make the bed ways level to the world. A drawing shows a 6" Atlas lathe, sans the carriage and tail stock. (i know this is a 6" as it only has 1 mounting bolt hole on the right hand bed foundation. (facing the lathe) On the bed are 4 machinist's levels. (of course, this is only showing the positions 1 level is positioned for this test.) The positions shown are across the bed close to the headstock, parallel to the bed ways near the center of the bed, and across the ways near the right hand end of the bed. This level is a precision machinist's spirit level, such as a L.S. Starrett No. 96. A sensitive level should move the bubble about 1/8" when a .003 shim is placed one end of the level. Shims (1" x 4"), metal or cardboard, should be placed between the bench top and foundation around the bolts on the headstock end. (a notch to accommodate the bolt is shown .) Shims are placed on either side of the bolt on the tailstock end. These shims should be added/removed to achieve level. I'm sorry that I can't post a picture of the page, but my WebTV (c) Microsoft won't let me do that! (boo-hoo, baby!) Leo ------- (Atlas E-group files) Leo, I posted a couple of pages out of the manual for you. Jus tryin' to help out.... Bill C. Files: "Clemens's Iron Stuff" ------- Date: Sat, 25 Nov 2000 10:24:44 -0600 From: Subject: Re: 6-18 [atlas_craftsman] > On 19 Nov 2000, Den & Betty Haas wrote: > > I have a 6-18 Atlas that I took out of the crate from the factory > > in 1977. Been lurking on this list & the serial nos. I have don't > > seem to jibe with what I see. Here are the specs on what I have. > > SN 3950 Mod. No. 002328 Number on the bearing that I can see on > > the chuck end of the headstock is NTN 620SLU. This lathe came with a > > square, plastic gear cover that has since been melted in a fire. It > > came with a Dayton Mod. 5K261B, 1/3 hp motor. 1725 rpm, 115v. > > Can anybody enlighten me as to what I have & when it was made? > > Thanks Den Den & Betty Haas Nov. 25, 2000 From: "Marty Escarcega" > You have what appears to be one of the last incarnations of the > lathe before it was discontinued by Clausing. Our group still > supports it, but admittedly most everyone has one of the older > machines. Use it and enjoy it, if we can answer any questions at > all, please feel free to ask. Marty, Moderator Atlas_Craftsman Group I saw your post on the model 3950. Advertised dimensions are 6 x 19 inches, with 1-10 thread headstock spindle. I have the same model. It was made between 1977 and 1980. this the next to the last model. The last model was painted blue and included an all-metric version, very rare now. NTN is still in business. You can cross-reference the bearing number if you need replacements. Get on www.thomasregister.com to track them down (free). Dayton is now owned by W.W. Grainger, a huge supply firm. You may be able to cross reference the motor if you need replacement. Grainger website can be hunted up. Atlas sold a variety of motors, mine is by Westinghouse Electric. > >First thing is contact Clausing Service Center to get in touch with Technical Support. Ph 219-533-0371, e-mail joldsx~xxclausing-industrial.com Tell them what happened and get PRINTED information on what to do (FAX or Mail). Get prices on replacement parts and accessories (free!), like the melted cover. If parts are discontinued, contact Technical Support for substitute sources or dimensioned drawings so you can make your own parts. Also, ask Technical Support to get wiring diagrams for hooking up the reversing drum switch Clausing sells for the motors. The diagram needs to be specific for your motor. The switch is a Furnas Electric Style A-14. I think Furnas is still in business, check with them if needed. Contact through thomasregister site. > Important tips, a rigid base or bench with plenty of width is advisable, with swiveling leveling feet on each leg. If the base is narrow, go with heavy gage steel or cast iron machine bases. Tighten screws on lathe bed feet in small increments while watching the precision level bubble. The lathe bed can be tension sensitive. Shims alone without checking tension is not successful. >Use way lubricant, instead of ordinary motor oil on bedways, side gib,dovetail surfaces, and clamps of carriage. It will eliminate "chatter and "stick slip" when threading or power feeding. A drop or two on the carriage gear contacting the leadscrew really smooths things up. Use the minimum, because the lube is very sticky. Mobil Oil makes "Vactra" brand in a 1 gal. and 5 gal. sizes. Other makers make similar way lube products. >If possible, get the threading gearsette accessories. One set will let you make coarse thrteads down to 5 threads per inch. An important consideration if you need to make parts for larger size lathes. Even the expensive Myford 7x19 lathe from England can't do this!! E-mail me if your need more tips on this lathe. James Sprott ------- Date: Sun, 26 Nov 2000 16:19:47 -0000 From: "William Clemens" Subject: Re: new owner "Franke, Jim" wrote: >Hi, I'm Jim. I am new to this group. >I just recently purchased a 6" atlas lathe and am very excited about >getting it up and running. I had spent approximately 2 1/2 years building >one of the Gingery home made lathes and it works well, but I have gotten a >little frustrated with it. It requires quite a bit of attention for every >operation and is not always reliable or predictable. I was very lucky >and found this atlas lathe for a modest price compared to what they were >selling for on ebay. Plus it already has thread cutting capability and I >would have to build the Gingery miller and dividing head in order to make >change gears for my home made lathe. Enough back ground I guess. >In cleaning up and inspecting this atlas lathe I did find something that I >hope someone out there can help me with. The carriage seems to move less >than smoothly when operated with the hand wheel. It appears that the rack >attached to the lathe bed may have some damage to it in a few spots. I >attempted to remove it by removing the retaining screws but there appear >to be 2 pins, 1 at either end that that also secure it. I was afraid to >pry on the rack to losen it for fear of bending it. My question then is, >are these 2 pins just alignment pins or are they screws that feed from the >inner side of bed, and what is the best way to remove the rack so I can >replace it or repair it? Thanks. Jim Jim, The older atlas machines used taper pins for alignment and for a greater shear proof attachment of the rack to the ways. An old trick was to turn the rack end for end to bring the outer portion into use close to the headstock where most of the work is done, but I don't think you can do that with the 6" machine( I'm going to check mine to see for sure). You should be able to pry it loose (evenly) with a very small heel type pry bar, or well placed heel blocks close to the rack. It is mild steel, so you may be able to do some touch up to it...You should remove the saddle to do this you know. Bill C. ------- >> I saw your post on the 6 inch Atlas lathe. I had a similar problem with my 3950 model., only in one spot near the headstock. Before prying loose the rack, try this quick fix! One or 2 drops of way lubricant on the carriage gear that engages the rack. It should slide right over the trouble spots! I used "Vactra" brand from Mobil Oil. There are similar way lubricants from other makers that will do the job. Try the Travers catalog at www.travers.com or local industial oil and lube supply firms in your area. If the problems persist, contact Clausing Service Center and ask for Technical Support. Give lathe model and serial number and get specific instructions on how to fix the problem. Design changes in my model show staked in pins, not taper pins holding the rack to the bed casting. No prying without problems on my model! To avoid expensive damage, check with Technical Support first, before prying on anything! James Sprott << ------- Date: Sun, 26 Nov 2000 21:50:15 -0500 From: A J Palik Subject: Lathe Bed Wear This is a letter I wrote about a year ago. It may be of help to others. I was having trouble turning a 1" steel shaft in my 10"x 24" Atlas lathe.I am new to lathes and wanted to check out my lathe and see if it was turning a taper or was running true.The steel was an old piece of line shaft.It isn't very hard so I chucked it up in my 4 jaw chuck and set the live centre in the tail stock.Starting at the tailstock and turning towards the headstock all was going well until I got about 4" down the shaft--the shaft is 16" long.The curls were rolling off the steel tool bit as pretty as can be and slowly but surely the tool bit started to chatter. The further I turned the shaft the worse the chat- tering got. I tried everything ,different tool bits, carbide bits, different turning speeds, heavy cuts, fine cuts. Nothing helped. Now mind you that this Atlas is an old one and well used.I tightened the saddle gibs near the headstock but found that the bed was worn and had to lossen the gibs so the saddle would run the full lenght of the bed.I resnugged the gibs near the tail stock.The chattering didn't get any better.I have read that a lathe bed must be trued up by scraping,something very few master so that was out.Me being a cheap old fart took matters into my own hands and got out my files.I selected a very fine cut file and my trusty old file card.I tightened the saddle gibs near the headstock and slowly slid the file down the sides of the ways, taking light cuts on both sides of the ways(front and back). After every stroke of the file I cleaned the teeth of the file with the file card. Every few minutes I checked my progress by wipping the ways off,lubing them with oil and running the saddle down the bed.Slowly but surely the saddle would travel futher and futher down the lenght of the bed.After about an hour and a half I got the ways true and now it was time to test out my work. I now have a lathe that will cut a 16" shaft to within .001" from tailstock to headstock and no chatter.Maybe I was lucky with this method but thought I would share my ways trueing method in case it could help others. ------- Date: Sun, 26 Nov 2000 22:01:24 EST From: loon432x~xxaol.com Subject: Newbe (sort of) This is my first posting to the group, but I've been lurking for about a year now. I have an Atlas model 618, serial # 025953. It was in pretty bad shape when I aquired it. The bed was slightly warped and someone had beat on the ways with a large file. There were no chucks. The quill lock for the tailstock was missing. The compound and crossfeed handles were broken. Plus the carriage feed gear didn't mesh correctly with the rack, so it tended to top the teeth off of even a new pinion. It did have a face plate, change gears, wrench, and a few spare parts including a new crossfeed screw and nut and set of half nuts. And the price was right--it was given to me after asking the right questions. You wouldn't recognize it now. I have rebuilt and repainted it. I had to machine the ways to correct the warped area and remove the file dents (about .015 off the top and .005 off the sides). All 4 surfaces of both ways were machined in one setup. The carriage was belled about .003 so that was machined out and it was also corrected for the new thickness of the ways. The compound gib did not seat correctly so the dovetail was machined also. The mounting holes for the carriage gearing were bored off center and bushed to move the gearing into correct mesh with the rack (on a Sherline 2000 mill believe it or not). I made a new tailstock quill lock with radiused contact surfaces instead of chamfered. New handles were made from stainless steel. Every mating surface (including gibs) has been scraped in and the lathe now meets tool room lathe specs. I got origional Pratt Bernard 3 and 4 jaw chucks from Kitts Supply when they still had them. The 4 jaw, which was 3/4-16, had to be bored and rethreaded to 1-10. This was done by mounting the chuck on the face plate with it's own jaws and indicating it in after making an exact copy of the spindle threads to check it with. I would highly reccommend the book MACHINE TOOL RECONDITIONING by Edward F. Connelly. It tells you how to scrape and make scrapers and has step by step proceedures for rebuilding a lathe, milling machine, and grinding machine. It is well worth what ever price you pay for it. ------- Date: Tue, 12 Dec 2000 20:19:28 -0500 From: "ebower" Subject: Re: Sears/AA Lead / crossslide screw threads? Mike, The leadscrew for the AA is the same as the Atlas 6". The thread is 1/2-16 ACME RH Stub. I have chased these in the past. I have also made a replacement for my 6" Atlas. I have both lathes. If you want to buy a leadscrew, contact Clausing and ask the price of the 3950-16 screw collar assembly. You will have to shorten the leadscrew (on the bearing end) because the Atlas 6" is approximately 24" long. I had special acme cutters made to chase these threads. They must be done on a lathe other than the AA. Earl ------- Date: Fri, 22 Dec 2000 00:41:07 -0000 From: "Tim Clarke" Subject: LEVELING, c'mon you guys! Some time back, there was an article in H.S.M. about setting up your lathe. The author said a few thing that really made sense, one being that on small, flexible bench lathes, the load applied during cutting can't be ignored. Another was that being dead nuts level isn't near as important as removing twist. What I did after reading the article, was to level with my machinist level, and it ain't a master precision. Then I made a upright clamped to the toolholder about 2 feel tall. From this I hung a homemade plumb bob. I laid a steel scale underneath held to the crosslide with a magnet. Then, by cranking the carriage to the extreme limits of it's travel, I discovered I had a twist in my bed. I cut shims from sheel metal, tin foil, and plastic from the recycle box. I guess the whole effort lasted about an hour. After leveling, I adjusted the tailstock as described in a couple of previous posts. There is little need to spend a bunch of your beer and bait money on something you'll use infrequently and don't really need. There is usually a way around any rule chiseled in stone, and it has always amazed me how simple it seems when someone tells me. Many thanks to the now forgotten old geezer who shared this with me, and I hope that this works for you as well as it has for me. Regards, Tim in Oregon ------- Date: Fri, 22 Dec 2000 14:35:47 -0500 From: Jude Miller Subject: Re: LEVELING, c'mon you guys! Jim Irwin wrote: > 'Taint that hard, pard. To work best, a machine has to be straight and > square with itself according to its design. To get it to that ideal > condition, you have to have some reference point. You could use the > north star just as well. But most folks find it easiest to use > Mother Earth's force of gravity as a semi-permanent > reference. The instrument of choice for this is a level. > However, one can use the > 2ft long plumb-bob and accurate scale method quite nicely. > 0.005 x 2 ft is 0.010...certainly easy enough to see with a good > scale (I'd need a magnifier, though!). > My level is an English 6 incher divided to 0.005in per ft. > Master levels divide to 0.0005. How much precision do you want? > One would drive himself crazy trying > to level to 0.0005 using shims, as they are much thicker than this. > I level the bench my lathe is mounted to. The bench is 2 1/2 ft deep > and 4 ft wide. With my level I can detect a sheet of paper under > any mount foot. Best regards, Jim Irwin Yeah, but if you want to turn to within a thou, you need less than 0.0005 (1/2 of 0.001 inch) variation in the tool position as you move along the bed. On a 12 inch lathe, that corresponds to roughly the same amount of twist in the bed. If the headstock end of the bed is level (front-to-back, not along the length of the bed), then the tailstock end must be level within +/- 1/2 thou per six inches. This is almost as close as you can measure with a master precision level. If you level with a coarser level, you can easily have several thou of twist in the bed, meaning you will turn a taper of up to twice that. There is another method, called Rollie's Dad's method, which doesn't use a level. I've included it here as text. RDM probably doesn't work as well as a really good level, but it doesn't require one either. This is one of several descriptions I found on the 'Net. Best, Jude Miller ------- Rollie's Dad's Method of Lathe Alignment Copyright 1997 by New England Model Engineering Society. What you need: A round bar The bar length should be about 1/3 to 2/3 the bed length. The bar must be of one diameter along most or all of its length. The bar does not have to be completely straight. Since Rollie has a car repair shop, he uses the shafts from junked shocks and struts. A dial indicator The end of the measuring rod should be flat. A means of mounting the indicator on the cross-slide. To do a vertical alignment the mount must be adjustable. A chuck of any type to hold the bar. Runout in the chuck is not a problem (for the same reason that a slight bend in the rod is not a problem). What you DON'T need A tailstock, perfectly straight bar, a collet or precision chuck or any tool bits. Applying the method (Horizontal Alignment) 1. Put the bar in the chuck. 2. Mount the dial indicator on the cross-slide at the center height of the lathe. 3. With the carrige near the chuck end, adjust the cross-slide so that the indicator reads a convienient "zero" value like 0.100 4. Turning the lathe by hand, adjust the cross-slide so that whatever runout you have is equal on both sides of your "zero" (say .105, .095). 5. Pull the indicator's measuring rod back by hand to clear any irregularities and move the carrige to the other end of the bar. 6. If the runout is not also centered there (say .110, .098) then your lathe is twisted and a foot should be shimmed. 7. Repeat from step 4 until runout at both ends is evenly divided on either side of your "zero". Applying the method (Vertical Alignment) 1. Put the bar in the chuck. 2. Mount the dial indicator on the carridge so that it is directly above the center line of the spindle. 3. With the carrige near the chuck end, adjust the indicator mount so that the indicator reads a convienient "zero" value like 0.100 4. Turning the lathe by hand, adjust the indicator mount so that whatever runout you have is equal on both sides of your "zero" (say .105, .095). 5. Pull the indicator's measuring rod back by hand to clear any irregularities and move the carriage to the other end of the bar. 6. If the runout is not also centered there (say .110, .098) then your lathe is twisted and a foot should be shimmed. 7. Repeat from step 4 until runout at both ends is evenly divided on either side of your "zero". Why This Method Works When the runout is evenly divided, at the zero point the runout is entirely in the vertical plane and the side of the bar is exactly one bar radius from the turning axis of the spindle. If the runout is evenly divided at both ends of the bar, the spindle is rotating in a plane parallel to the ways. Common Error Some people will turn the lathe to the point where the indicator reads "zero" and then move the carridge down to the other end to see if it still reads "zero". That method will only work if your bar is known to be perfectly straight. Do not confuse that method with this one. I learned all this from a fellow member of the New England Model Engineering Society. Join us the first Thursday of every month at the Charles River Museum of Industry in Waltham, Mass. ------- Date: Fri, 22 Dec 2000 17:32:41 -0500 From: Jude Miller Subject: Re: Re: LEVELING, c'mon you guys! cdhintonx~xxmsn.com wrote: > If the lathe is off in the vertical- doesn't this indicate that the > lathe is sway backed or humped back? And how would shimming a foot > correct this? Craig If the lathe has a hump or a sag in the bed, then the level will read differently if placed on the long axis of the lathe at the headstock and tailstock ends. This is less serious than twist, since the cutting radius is little changed by vertical misalignment. A vertical error of 5 thou on a workpiece 0.5 inches in diameter increases the diameter by about .0001 [this figure corrected per following follow-up e-mail from Jude Miller]. The same error horizontally changes the diameter by 10 thou. Depending on the feet, they may be shimmed under the sides and the end to remove misalignment. The idea is to shim e.g. the middle of the far end of the tailstock foot higher than the part toward the headstock to decrease hump, lower for sag. Best, Jude Miller ------- Date: Fri, 22 Dec 2000 17:38:58 -0500 From: Jude Miller Subject: Re: Re: LEVELING, c'mon you guys! Slipped a decimal place there. A vertical error of 5 thou on a 1/2 inch workpiece changes diameter by only about a tenth (0.0001 inch). The horizontal error is correct at 10 thou. Best, Jude Miller ------- Date: Fri, 22 Dec 2000 20:05:23 EST From: catboat15x~xxaol.com Subject: Re: LEVELING, c'mon you guys! In a message 12/22/00, jmreidx~xxu.washington.edu writes: >The point of levelling is not just to do it on the length of the bed, >but also to check for twist by using the level crosswise at both ends. On my 12X48 Craftsman/Atlas there are only three mounting holes, two under the head stock and only one in the middle at the tail stock end. Never worried too much about this, and I remember some article in an old Model Engineering magazine that recomended this type of mounting for a Myford of about the same dimensions. The method recomended there was to bolt the headstock end down tight, but leave the third mounting at the tailstock a little slack, just enough to keep the lathe from walking off the bench. So that is the way mounted my lathe. John Meacham ------- Date: Mon, 22 Jan 2001 00:28:29 -0600 From: Jon Elson Subject: Re: Carriage adjustment? mfb1fyfbx~xxteisprint.com wrote: > I need to adjust the Carriage (it moves between the head stock & tail > stock, with the long lead screw) The cross slide mounts on top of > it? The Carriage, cocks back& forth, when not connected to the lead > screw? When I take a cut along the lenght of a 3/4" dia of Aluminum, > the same amount of materical is remove over the lenght of the cut. > Can only find ONE setscrew to adjust (on the back side, the side W/O > the handle, for moving. On the tail stock side of the carriage. The gibs nobody knows about are UNDER the carriage, and prevent it from lifting up from the bed. There are two iron (I think) plates held on with 2 screws each. Under part of each plate are laminated shims. Sometimes people take these apart and get the shims caught on the screws, causing the shims to wrinkle and prevent the plates from riding close to the bottom of the ways. On the back of the carriage there should be 4 gib adjusting screws to adjust front-back free play of the carriage. You have to set this for the LEAST worn part of the bed, or it will cause binding when it gets to the least worn part. There should also be 4 gib adjusting screws on the right side of the upper part of the cross slide casting. I hope this info helps. this info should apply to either 10 or 12" Atlas or Atlas/Craftsman lathes. > Cannot remove the carriage from the lathe, W/O disassembling the > lever to engage the lead screw? Hope this explains it, better? To remove the whole carriage, there are several ways to go. You can disassemble the half-nuts, remove the bottom gibs and lift straight off. You can remove the right-end bracket for the leadscrew and pull the leadscrew straight out to the right (if you have enough room over there). Again, you can now lift straight off after removing bottom gibs. Or, you can remove the two large Phillips-head screws in the top of the carriage, disconnecting the apron from the carriage. Then, remove bottom gibs and lift. It depends on what you want to look at as to which is the desired method. Jon ------- Date: Sat, 17 Feb 2001 06:24:42 -0000 From: hhrjx~xxhome.com Subject: Re: Swapping Lead screw end for end "Jerry Halcomb" wrote: >>Someone on the list said his leadscrew was swapped on his 10". As far as I can tell on my 3983 model atlas 12" it can't be done. The right hand end is smaller than the left end so unless metal can be added I don't see how. I am open to suggestions rather than spending $284.00 on a new lead screw. Jerry << Jerry, adding metal to your leadscrew shouldn't be a problem if you have the capability to heliarc weld. I've used this several times in the past on shafting and dies. I don't know the difference in diameter between the ends but if it's not too great you might try metal spray to add material. I had a worn fire pump shaft sprayed and then turned to the original diamenter, worked great. Cost can rival that of new parts however. Ron Jones ------- Date: Sat, 17 Feb 2001 21:42:45 -0800 From: escarcegax~xxhome.com Subject: FORW: Lathe bed milling Guys, I know this fellow. If any of you have been contemplating a bed regrind of your Atlas_Craftsman lathe beds contact him. My money says he'll shoot a better price on these beds because they are flat and not prismatic. If anyone contacts him, report back as to price. IF anyone has him do a bed, let us know how it went. Marty Found this in rec.crafts.metalworking: == BEGIN forwarded message == Subject: Lathe bed milling From: Michael Morgan <40pointsx~xxhome.com> Newsgroups: rec.crafts.metalworking This is a sales pitch so quickly avert your eyes! If you have an old lathe and are interested in scraping it to restore the alignment of the beast, you have no doubt found that the hardest part is the bed. Professional rebuilders almost never scrape the bed of a lathe except for final touch up. We machine or grind them. If you would like your lathe bed machined please let me know. I have the machine that can do it and do it cheap. OK so I think it's cheap, you may think I am a highway man. How cheap is cheap, how about a 10X60" South Bend with soft ways for $300.00 One note: I can only do this for individuals. Companies must hire my company for this work, but if you have a lathe in your garage that needs some TLC now is the time! Thanks and all of those who looked away to avoid the sales pitch may now look back again. Mike ------- Date: Sun, 18 Feb 2001 11:21:24 -0500 From: Jude Miller Subject: Re: FORW: Lathe bed milling escarcegax~xxhome.com wrote: > I know this fellow. If any of you have been contemplating a bed regrind > of your Atlas_Craftsman lathe beds contact him. My money says he'll shoot > a better price on these beds because they are flat and not prismatic. If > anyone contacts him, report back as to price. IF anyone has him do a bed, > let us know how it went. I assume he's talking about milling the bed rather than grinding it? Does this give a smooth enough finish for a lathe bed? He quoted me $180 for a 6 x 18 bed (i.e. 30 inch unhardened bed with flat ways). Best, Jude Miller ------- Date: Sat, 04 Nov 2000 08:24:40 -0500 From: Ronald Thibault Subject: Re: What to look for when buying lathe If you have a micrometer or dial caliper, measure the bed ways as follows: 1. Across the vertical surfaces of both the front and back ways. 2. Distance between the 2 inner vertical surfaces. 3. Thickness of ways at the front of the front way, and the back of the back way. 4. distance from the top of the ways to the sliding surface of the carriage. Do this at several locations along the bed. The most important measurements are the width of the ways. Any wear here will directly affect the ability to turn a constant diameter piece. The thickness is not nearly as important, but the more uniform the better. The distance from the way to the sliding surface of the carriage, is an indicator of the wear between the two, excessive wear means the bed is probably also shot. The distance between the inner vertical surfaces indicates whether the tailstock will be accurate in its' positioning. Generally though even a badly worn bed will still be good here. The tailstock gets moved orders of magnitude less than the carriage. A couple thousandths wear between the vertical surfaces of the bed, is not too bad. You can compensate for this, with some time turning on that lathe. Much more than this though, should cause serious thought about the purchase. In general look at the sliding surfaces of the rest of the lathe. The more the original grinding marks show, the better. The top of the bed was originally ground smooth, but the rest of the surfaces have a hash mark look (look at the inner way vertical surfaces, for an example). Good luck with your inspection! Ron Thibault ------- Date: Sat, 10 Mar 2001 13:30:18 -0500 From: Richard Meredith Subject: New acme thread lead screws I have been a non participating member of this group for some time. I read each post with interest, and have picked up a great deal of information. Several times people have asked about sources for new lead screws. I have dealt with a small firm that specializes in Acme thread stock and nuts in Two Rivers WI for many years with good results. They do not cut or machine the material, but do sell UPS able lengths of just about any Acme thread. The firm is: Green Bay Manufacturing 2617 18th Street Two Rivers, WI 54241 Phone: (920) 793-2411 They do not have an internet presence that I know of, so you will have to contact them by phone or mail. I hope this will help, and Good Luck! ------- Date: Mon, 12 Mar 2001 19:11:48 -0800 From: "John Johnson" Subject: Interesting Pattern I am the second owner of a Craftsman 12x36 lathe with cabinet stand (M/N 101.28990, S/N 108009) that I have had for about three years now. The first owner bought it new from Sears about 1975. Yesterday while turning the axles of my live steam Shay, I noticed an interesting pattern that repeated along the cut every 1/8". I figure that it is related to the lead screw somehow. It appears to be some kind of light wave or disruption to the otherwise smooth cut. I was turning steel about 1.250" diameter down to 1.125" diameter. Using a carbide insert cutting tool and a quick change (phase II) type tool post taking off about .015" at a time. I was using the slowest feed rate available with the quick change gearbox (.0042" per rev). The cut was about 6" long. The axle was held on one end by the 3-jaw chuck and with a live center on the other end. It is not real objectionable and will get covered by paint, but I was wondering if this means I have some- thing worn out. I did replace the half nuts about two years ago so I know they are in relatively good shape. The lead screw looks fine, but maybe it has a bend in it that might be binding something some where? I have not explored the QC box to see if there is anything in there that looks wrong. Any ideas? John D.L. Johnson Chico, California www.LocoGear.com ------- Date: Mon, 12 Mar 2001 22:53:16 -0500 From: "Wayne" Subject: Re: Interesting Pattern John , I have sometimes noticed a swirling pattern on short and longer turns on my 12x42. I have always thought is was in the mfg. process of the metal I was turning? I found today that my headstock bearings were a little loose, so I have tightened them up, but have yet to turn any of the same stock to see if that was it. Try this... remove the chuck and try to wiggle the head/main shaft. If you can feel a slop, work on the bearings. It is a simple procedure and I'm glad i caught mine .Good luck and keep us posted. Wayne(rice)Burner ------- Date: Mon, 12 Mar 2001 22:07:56 -0600 From: "J Tiers" Subject: Re: Interesting Pattern Possibly you have a slightly loose carriage, and the lead screw usually holds it down except at one point of its revolution, maybe a slight bend and that is the high spot. If it looks like a phonograph record, ir is probably a chatter mark, even if you don't hear or feel a chatter. You should be able to adjust the gibs, unless you have a worn spot on the bed. Try slathering some extra way oil on so it is under the carriage before the next such cut, and see if that helps. If so, probably looseness. Jerry ------- Date: Tue, 13 Mar 2001 00:12:47 EST From: catboat15x~xxaol.com Subject: Re: Interesting Pattern jjohnsonx~xxlocogear.com writes: > , I noticed an interesting pattern that repeated along the cut every 1/8 If the pattern looks like a rope or something similar it is chatter doing that. Try changing feeds, speeds etc. Once it starts it is sure hard to get it to stop what I call roping. John Meacham High Desert of California, Palmdale, Littlerock. ------- Date: Tue, 13 Mar 2001 00:34:16 -0600 From: Jon Elson Subject: Re: Interesting Pattern Yup. They all do it! Well, pretty much, anyway. It mostly shows up when making the final finish cut. I usually only see it when making a fine cut with a toolpost grinder. There are a couple of things you can do about it. First, run the lathe with the screw driven, but the carriage half nuts open, and look for an orbiting of the leadscrew. Some of them are bent, or have a little sag in them. This will cause the carriage to rock a little bit. If the screw runs true, then clean the threads and the key slot carefully with a rag or soft tool like a screwdriver blade, to dig all the chips out of there. Lube the screw well and try again, with the half nuts engaged. If the screw appears to move around, rather than running true, you should take the crossfeed drive and the halfnuts apart and clean and relube them. Swarf in the halfnuts and crossfeed drive can force the screw to move around and exert force on the carriage. Finally, if the carriage is loose in either the forward/back or up/down directions, a small pressure from the leadscrew can make it wobble on the bed, disturbing the trueness of the cut. Most likely not the QC box, unless the screw has something jammed between it and the collar that it fits into, or some other interference is binding the leadscrew so it doesn't run true. That is possible, though. You would see the screw 'orbiting' if this is the case. Jon ------- Date: Tue, 13 Mar 2001 09:17:48 -0800 From: Frank Evan Perdicaro Subject: Waves... My 10" Atlas has a worn 3-jaw chuck, a loose carriage, a heavily worn bed and a bent leadscrew, so I know why it does not make mirror finish parts. But keep this in mind. The leadscrew is being driven by straight-cut gears. The rotary motion through a straight-cut geartrain is not linear! You will never get smooth motion of the leadscrew with the gears these lathes come with. Sure, the variance is small but it never goes to zero. ------- Date: Tue, 13 Mar 2001 13:27:16 -0600 From: Jon Elson Subject: Re: Interesting Pattern Ah, you must have babbit bearings, then. On the Timken bearing lathes, the same tapered roller bearings handle both axial and radial loads. If your thrust bearing were rough, you would be able to feel it when turning the spindle manually. I think it is pretty hard for the babbit bearing to develop roughness this way, as the rotation of the lathe would smooth it off pretty quickly. It could be some vibration from the gear train that drives the leadscrew. But, it could also be tool vibration, or possible deflection of the workpiece. That is a common problem. Are you using a sharp-pointed tool, or does it take a wide cut? If the cut is too wide, it will cause vibration on these lighter lathes. Jon ------- Date: Tue, 13 Mar 2001 16:52:06 -0600 From: Jon Elson Subject: Re: Interesting Pattern Jude Miller wrote: > Oilite spindle bearings, ball thrust bearing. The spindle > turns smoothly, the roughness is noticeably if I load the > thrust bearing by pushing the spindle toward the headstock as I turn. Ahh, I thought you had mentioned it was a 10" Atlas, but this is the 6". If the bearings are bad, then you need to replace them. A small ball thrust bearing is not a very expensive item. > I've should probably replace it, but I don't want to remove > the spindle again. Last time around, I was in too much of > a hurry to get the lathe running to wait for the replacement. Well, if you are not happy with the results, then I think you need to replace that bearing. It should not be a big job. Jon ------- Date: Wed, 14 Mar 2001 01:31:57 EST From: sleykinx~xxaol.com Subject: Re: Digest Number 420 This may sound strange but, are your ways well oiled? A good way oil makes a big difference in that type phenomenon. Attribute it to "sticktion" .. the carriage is supposed to ride on a film of oil and if the oil isn't tough enough or enough of it there you can get some strange patterens ... the kind you can see but can't feel/measure (with any of my measuring sticks anyway). Good luck Glenn ------- Date: Thu, 15 Mar 2001 08:23:47 -0800 From: "John Johnson" Subject: Re: Interesting Pattern Thanks to all who responded to my post. I think the collective wisdom is a slightly bent lead screw and loose gibs causing the carriage to rock a bit making the rope like pattern. I'll have to spend some time this weekend checking it out. Thanks, John D.L. Johnson www.LocoGear.com ------- Date: Sat, 24 Mar 2001 22:38:59 -0800 From: "Larry Bailey" Subject: Re: Eliminating Carriage Slop >From: airxxxwolfx~xxyahoo.com >On my 6" 101.07301 lathe, the backside of the carriage has some >vertical play. I checked it out and found that the upper gib >was a little wider than the thickness of the way, and that there >was a gap of a few thousanths between the bottom gib and the >underside of the way. I carefully filed the bottom edge of the >upper gib until it fit perfectly against the edge of the way >without protruding past the bottom edge of the way. This enabled >the bottom gib to move closer to the underside of the way, but >not quite close enough. Using a dial indicator, I can pull up >on the carriage with the indicator reading .0025 of play. What >is the best way to remove this play? It looks to me that the >carriage would need to be milled a few thou where the bottom >gib bolts on, and then the gib shimmed to proper fit. Is this >the way to do it, or is there another way? Regards, Don Smith On my 12" there are brass shims in the 0.002-0.003" range to close this space. One uses the correct shims to fill the space while still allowing the carriage to travel smoothly. Check your parts diagrams. You probably need something similar. Larry ------- Date: Sun, 25 Mar 2001 08:06:51 -0500 From: "Trammell, Rex" Subject: RE: Eliminating Carriage Slop Yes, the six inch works the same way. These shims are easy to cut so you can make your own. The only limit on how well you can fit the carriage is bed wear. You set the shims so that the carriage is snug where the bed is not worn. The carriage will then be looser where the bed is worn thinner. Rex ------- Date: Sun, 25 Mar 2001 08:55:12 -0800 (PST) From: Don Smith Subject: RE: Eliminating Carriage Slop I think there`s a misunderstanding of the problem on my carriage. Adding shims will "increase" the slop in my carriage, and removing shims will "decrease" the slop in the carriage. In other words, the bottom plate that rides along the underside edge of the way, will be farther away if I add shims, creating more slop. The more shims you remove, the less slop you have in the carriage, because removing shims brings the bottom plate closer to the bed, while adding them moves the plate away from the bed. The problem is that I can`t get the bottom plate any closer to the bed because there are no more shims to remove Don... ------- Date: Sun, 25 Mar 2001 13:02:47 EST From: LADDERBARx~xxaol.com Subject: carriage play Look at the plates to see if there is any wear in it, if there is turn it over to the side that doesn't have any. (Take a stone to it to remove any burrs.) If play still exists look for wear on the bed rails or the carriage itself. Happy chip making. ------- Date: Sun, 25 Mar 2001 10:30:26 -0800 (PST) From: Don Smith Subject: Re: carriage play The plates are in perfect condition. As far as I can see, on my lathe the problem has to be either a worn bed, or a worn carriage. The only way I can see of correcting the problem without replacing the bed or carriage, is to mill a few thousanths off the bottom edge of the carriage where the bottom plate bolts on, and then just simply shim the plate to suit my needs, or make a special plate with a step on it. ------- Date: Sun, 25 Mar 2001 15:19:05 -0500 From: "Trammell, Rex" Subject: RE: carriage play You seem to understand how it all works but it still seems strange. The stack of shims is quite thick so the bed or the carriage would have to wear a lot in order to cause the condition you describe. If the bed is worn that much it will probably not be worn uniformly so achieving a snug fit from one end to the other will be hard. Also, since the bed only wears in the area where the carriage contacts, outer 3/8 inch or so, there would be a visible step showing the wear. If the wear is in the carriage itself milling off the bottom edge would fix the problem. The idea of a special plate with a step sounds good since you aren't risking anything very expensive to try it. Be sure to let us know how it turns out. Rex ------- Date: Sun, 25 Mar 2001 17:27:58 -0800 (PST) From: Don Smith Subject: RE: carriage play Hi Rex, Actually, my lathe, which I`ve only owned since last Tuesday, only had one shim between the plate and the carriage. This single shim was .0045 Anyway, I have solved the problem by milling the carriage where the plate bolts on. I only milled enough to suit my needs. The plate is now installed with no shims, and everything fits perfectly with no play, and the carriage moves smoothly. I could have milled some more metal off the carriage and shimmed the plate, so that as the bed wears, all I would have to do is re-adjust the thickness of the shims, but I decided to wait and do that next time. For now everything is fine the way it is. I measured the thickness of the bed, and starting from the tailstock end, and measuring about every 6 inches, I got readings of .430-.430-.429-.427 and .428 Since the .428 reading was right in front of the headstock, I was expecting a reading closer to .430 like the other end of the bed. My next job is to align the tailstock. Don... ------- Date: Sun, 25 Mar 2001 21:29:21 -0600 From: "J Tiers" Subject: Re: carriage play Poster wrote: >The only way I can see of correcting the problem without replacing the >bed or carriage, is to mill a few thousanths off the bottom edge of the >carriage where the bottom plate bolts on, and then just simply shim the >plate to suit my needs, or make a special plate with a step on it. I suppose you could turn the problem inside out, by putting a shim in, somewhat in the nature of a gib. That is, between the plate and the way. Then in order to get a reasonable thickness of the new "gib" , you can shim the plate out a bit. The "gib" can be secured several possible ways, including just bending up ears on the ends, or better, pinning it where a pin won't interfere. Jerry ------- Date: Mon, 26 Mar 2001 04:41:38 -0000 From: fyunchx~xxaol.com Subject: Re: Eliminating Carriage Slop HOw about milling a replacement bottom plate which is thinner where it attaches to the carriage, so that the other, unthinned part is higher than the bottom of the carriage? Then you can shim to fit. W.C. Gates ------- Date: Mon, 26 Mar 2001 00:17:27 -0600 From: Jon Elson Subject: Re: Eliminating Carriage Slop Right. I didn't reply before because I am only familiar with the 10 and 12" Atlas. Well, why is there so much clearance? Has the bed been reground, or has the carriage worn down that much? They usually gave a pretty generous allowance for wear, at least .015" to .020", at least on the 10". If the bottom gib has a groove worn where the bed rubs on it, you can flip the gib over and use the other side. If the bed is worn only in the most-used area, tightening the gib up too much will cause binding at either extreme end. If the bed is uniformly worn, or the carriage is worn down on the bottom, then you may have to either scrape down the lands the gibs attach to, or make a custom gib with a step in it. Other possibilities are to put shims under the carriage or wrap shims around the wear area on the gib, so that it constrains the carriage from lifting. Without knowing why the shim allowance is used up, it is hard to advise in a more specific way. Finally, you might want to find out what caused all this wear, and make sure you are using proper lubricants to prevent it as much as possible in the future. Jon ------- Date: Mon, 26 Mar 2001 14:05:58 EST From: anthrhodesx~xxaol.com Subject: Re: Eliminating Carriage Slop Don Smith wrote: << --- The problem is that I can`t get the bottom plate any closer to the bed because there are no more shims to remove. --- >> Sounds like maybe you have a late model carriage (for deeper ways) on an early model lathe. Firstly, you might try to find the correct carriage for your way depth measurement. Secondly, if you insist on trying to make this carriage work on your present lathe, measure the depth of your ways, then arrange to machine the matching part of the carriage to a few thou less than that measurement. When you reinstall it on the bed include a few shims to adjust the fit. In the future, presuming wear over a long period of time, you can then remove some of the shims to readjust the fit. That's the way the system is designed to function. Anthony Berkeley, Calif. ------- Date: Mon, 26 Mar 2001 09:16:07 -0600 From: "M K (Skip)Campbell Jr." Subject: Re: Dollar short, day late > I just wonder how to adjust the backgear/ backgear cover on it so > it don't rattle so much when I use it. I fixed a lathe I used to have that had that problem. I epoxied one of those little super magnets to the inside of the cover right at the edge so it locked to the headstock when closed. It worked like a champ. Regards, Skip Campbell Ft. Worth, TEXAS 12X36 101.28990 http://www.mkctools.com ------- Date: Mon, 26 Mar 2001 22:47:30 +0200 From: Jean-Claude Gerber Subject: Re: Dollar short, day late Hello John, Iīm not boating and therefore could not use it as an anchor! A piece of rubber of about 1/8" thick with contact glue on it and on the rim of the backgear case; wait until it is dry to the hand; hammer on the rim so that it glues down well, cut it with a blade to leave just a strip running on the rim and rattling has gone. Donīt sleep in after that, the workshop ambiance does so much change. Jean-Claude ------- Date: Wed, 28 Mar 2001 19:50:09 -0500 From: Ronald Thibault Subject: Re: Back gear bushing replacment At 10:09 PM 3/27/01 -0800, you wrote: > The first time I used my 10" with the new half horse motor it > stripped about 15 teeth off the back gears. Grrr. Sobel sold me > some good used gears and I am in the process of replacing the junk > parts. One problem area is the bushings in the back gear sleeve, part > 10-248. Atlas lists the "SLEEVE with bushings" and I can see why. > There appears to be no good way to remove and replace the bushings > in this part. My bushings are clearly quite worn (like every other > part of the lathe) and need replacement. > Has anybody replaced these? If so, how? I use a Pilot Bearing Puller for these tasks. This puller is used to remove the bearing in a flywheel in manual auto transmissions. front end of the transmission shaft fits into these bearings. It resembles a 3 jaw pulley remover, but with the jaws arranged to open from the inside of the bearing and locking onto the blind end of the bearing. I originally bough mine for, of course, removing the bearing in my Jeep. I've used it on occasion for just such jobs on my machine tools. They are not terribly expensive, and come in handy. Mine has a range of up to 1 1/2" ID and 1 1/2" long bearings. On my Atlas I had to turn the OD of the replacement bearings slightly. When pressed in they were compressed enough to bind on the backgear shaft. Ron Thibault ------- Date: Thu, 29 Mar 2001 00:18:48 -0500 From: A J Palik Subject: Re: anyone know?? jchodzkox~xxhotmail.com wrote: > hey all, i'm missing the thread protector that goes under > the set screw for the spindle assembly far left (threaded collar) > part#9-124.whats it made of?would a little piece of leather work? > also can anyone tell me the thickness of washer#9-87that goes on top > of the brass crossfeed nut? is it brass?took almost three weeks > via ups to get the cross feed nut.it went to texas on its' way to > calif.i want my machine back together and think it would drive me > crazy to wait so long for a washer. this is all for craftsman/atlas > 100-28990 underneath drive.thanks for any info. john To protect the threads under the set screw I use a piece of lead shot---a small lead ball that is used in shot guns---another thing that will work is a small piece of lead off a wheel weight----use your pocket knife and cut it down to size ------- Date: Sat, 14 Apr 2001 15:55:00 -0000 From: rweersingx~xxworldnet.att.net Subject: Re: 9" threading chart --- In atlas_craftsmanx~xxy..., "Dana Diller" wrote: >>> I need help. I was given a nine inch 1936 Atlas 918 Utility lathe. It is in good shape and I have it adjusted and working well. I can't find a gear change/threading chart. I have a manual for a 10 inch, but the gear info does not seem to fit. It is also possible that I did not get all of the gears or other hardware. <<< Hello Dana, many of the parts in the 10" lathe are the same as the 9" lathe. You may be able to use the 10" chart on the 9" lathe if you use some 10" parts. It would be helpfull if you could find someone in your area with a 10" lathe so you could compare the gear setup with your lathe. You can easily modify the 10" gears to fit the 9" lathe as per an Atlas bulletin at http://www.atlas-press.com/tb_chgrmod.htm I have an early model 10" lathe which is suppose to be like the 9" and I can freely change parts with my later model 10"lathe. lots of luck Bob ------- Date: Sat, 21 Apr 2001 06:49:46 -0400 From: Ronald Thibault Subject: Re: Back lash >>What is the back lash which should be allowed from the handwheel. Mine is approx. 3/8" which seems to me far too large. When I dismantled the whole carriage, I could not find any trace of wear on the handwheel shaft, neither in the train of gears going up to the pinion rack. I looked at the parts with a magnifier and did not see any trace of wear. Somebody knows about it ? << The gear train for the carriage handwheel has slots in the bracket. Loosen the three screws and slide the assembly towards the rack. >>Dials on the compound Rest and Carriage Saddle. They seem to act as a distance ring to block the play towards the handles. Has somebody made modifications so that the dials are much larger (the original are for kids with good rabbit eyes) and turnable to start a job on the Zero-Mark ? Thanks a lot for any help Jean-Claude << Look on my Web site (address below) for a short article on how I made a new zero adjustable dial for my cross feed screw. Ron Thibault North Augusta, SC USA Builder Miinie #2 Captain R/C Combat Ship USS Arizona http://pages.prodigy.net/thibaultr/ ------- Date: Sat, 21 Apr 2001 19:47:39 EDT From: steamclassx~xxaol.com Subject: Re: Bed Milling/Grinding>>How Much $$$ ??? Jeff..I Just had my 54" bed re-ground on my 10" Atlas and it cost me 175.00. But they also did the sides and got it all squared up. Pretty good price I thought. The company is Brown & Covey of Kansas city. John ------- Date: Wed, 25 Apr 2001 00:31:14 -0500 From: Jon Elson Subject: Re: "Squeak" gstonex~xxTECHLINE.COM wrote: >> I have a 12" Atlas that is 25 years old. After finishing a project the other day I noticed that the spindle is noticeable stiffer than it used to be and it has a "squeak" in what sounds like the left bearing of the head stock. My plan is to replace both spindle bearings and the drive belt. My questions: 1. Is there anything else that I should do while I have it apart? 2. Does anyone have any "pearls of wisdom" about the disassembly/reassembly? I do have the original parts list and the manual of lathe operation. << Before tearing the lathe down, make a disc that will fit into either end of the spindle, with a step at the right diameter to securely seat in either end. (That means, use something like 1/4" steel plate and put a shallow step on both sides. Also center drill in from both sides. You can then use a gear puller to drive the spindle out, and later, back in. Before pressing the spindle out, clean under the lip of the bearing inner races. I didn't do this once, and dirt was packed under the race (which is a LOT harder than the spindle) and it bound the bearing really well. I was able to back it off, clean, remove galling with a stone, and then try again. >> 3. Does anyone know the Timken part numbers so I could order the replacements before disassembly or is it wiser to have the parts in your hand when you go in? 4. The book doesn't show a cone for this bearing-does it come as a unit or are there separate bearings and cones? << Yup, you need 4 Timken parts, 2 inner races, and 2 outer. >> 5. I seem to have read somewhere that the lubrication of these bearings needs to be improved. Anyone have knowledge of this? << I'm using SAE #10, with a drip feed wick. If the wick gets gummed up or lost, you will get too little, or too much, lube flow. What you want is to fill the cup, and have it last several hours. The chip guards, if in good shape, trap a puddle of oil at the bottom of the bearings, so even when the cups run dry, there is still oil in the bearing. If the cups are badly gouged after several spindle pulls, you might do well to make new ones, or try to buy them. They are supposed to seat pretty well against the outer bearing bore to trap that puddle. Later Atlas manuals seem to now recommend SAE #20 oil, so I will have to switch grades. There are special machine spindle oils sold by the catalog machine tool supply places. Jon ------- Date: Thu, 26 Apr 2001 00:30:53 -0000 From: john.vanbrocklin2x~xxunisys.com Subject: Re: Help! Atlas 6" Hi..This is also my first post, but I have been lurking for awhile. Actually you are lucky both the nut and the screw are worn. I recently purchased the cross slide nut for the 6" and later had to order the matching screw since the older size thread is no longer made and the new nut didn't fit the old screw. Anyway, the old lathe is real tight now after replacing most wearables. John ------- Date: Mon, 30 Apr 2001 16:46:34 -0400 From: "Ebower" Subject: Re: Craftsman 6 in. Re-assembly Problems > When I finished re-assembling my Craftsman/Atlas 6x18 lathe, I noticed > some interference between the compound and cross slides. When I set > the compound at 30 degrees, as is my practice on larger lathes, the > cross feed handle hits the compound. The two slides only interfere > with one another when the crossfeed is in its last two inches of > travel toward the operator, but that does effecively reduce the > diameter of the workpiece to 3.5 or 4 inches. > I didn't pay that much attention to this part of the lathe when it was > together; I never used it before rebuilding it. Is this interference > normal or have I put something back together incorrectly? Do you set > the compound at more than 30 degrees for normal turning? I guess > threading is limited to smaller diameters, too. Thanks, Dave Dave, There are two possibilities that may be the problem. Whoever had your lathe before could have replaced the feed handle with a bigger one. The other possibility is that the spacer that should be between the carriage and dial is either missing or has been shortened up. My Atlas 6 x18 does not have your problem. My compound stays at 29 degrees for threading and I have had no problem of interference with the handles. The only time I have had problems is when I would set the compound at a 5 or 10 degree angle and try to machine. Earl ------- Date: Mon, 30 Apr 2001 15:43:39 -0600 From: "Maxwell Sandford" Subject: Re: Craftsman 6 in. Re-assembly Problems My 101.21400 has this problem. The handle on the compound interferes with the top of the cross-slide (not with it's handle) limiting the travel of the compound when it is set at 29 degrees. All parts are original and there does not appear to be any spacer missing. The compound attaches to the cross-slide with set screws that tighten against spacers that lock into the circular groove that is turned into the top of the cross-slide casting. The problem is that the compound is low enough that its handle interferes with the top of the compound thereby preventing the full compound feed range. There isn't any interference for threading because you can set the compound position within its range of available motion. There is plenty of range for thread cutting. The problem appears when you are trying to turn using the compound, for example if you want to cut a short taper. If the compound angle is significantly larger than 29, then the compound handle doesn't interfere. This looks like it is built into the design of these 6" machines. ------- Date: Mon, 30 Apr 2001 17:00:44 -0500 (CDT) From: dswrx~xxwebtv.net Subject: Re: Craftsman 6 in. Re-assembly Problems Dave, I have a 6" Craftsman/Atlas lathe that I bought new. It is normal for the Crossfeed Knob (ball end) to interfere with the Compound Body when the Compound is set to the 29 degrees recommended to cut a 60 degree V thread. However, it is only on the last two revolutions of withdrawal from the lathe center. That is only about 0.200", more or less. This lathe will only swing around 3" over the Crossslide in any case. I have turned a 3/4" thick steel plate to a diameter of 4", no easy task on a lathe this small! In fact, I can't remember how I did it! Around 50 years ago, so forgive me for faded memories. It was to make a Steady Rest that was featured in a Popular Mechanic's magazine. (The rest works great too!) ------- Date: Mon, 30 Apr 2001 21:28:06 -0500 From: Bill Aycock Subject: Re: Craftsman 6 in. Re-assembly Problems Gentlemen, for what it's worth, I just checked my Atlas 618, and the cross feed will crank back all the way (limited by threads inside cross feed) and the compound will rotate without interference. It is set to 29 deg, usually, but will not hit the crank (or vice-versa) with the cross feed back, and at any angle. It is assembled with the components shown on the parts list, as shown, because I had to replace the crank when I got the lathe. The crank had been broken in some rough handling, ages ago. Maybe the problem is only on some models, because it is not on mine. Bill Bill Aycock --- Persimmon Hill Woodville, Alabama, US 35776 (in the N.E. corner of the State) W4BSG -- Grid EM64vr w4bsgx~xxarrl.net ------- Date: Fri, 11 May 2001 19:39:02 -0000 From: doogdoogx~xxhawaii.rr.com Subject: Re: Gibs for late model 12 X 36 > In the process of rebuilding my Atlas 12 X 36 with Q/C I have > misplaced the gibs for apron, crossslide and the compound. > Clausing/atlas has replacements that are made of plastic. I prefer > metal. Does anyone spare metal gib strips for model 3983, 12" X 36". > Rod Reed Lafayette, LA I made my own out of 1/8" steel stock. If you have a mill it will make the job easier or a milling attachment for your lathe or last resort is the file. ------- Date: Fri, 11 May 2001 20:14:41 -0700 From: "John Johnson" Subject: Re: Gibs for late model 12 X 36 Last year I replaced my plastic gibs and made brass ones for my 12x36 A/C lathe. I did this by using a friend's milling machine. They were not that hard to make and I've really noticed a big difference in performance with the brass gibs over the plastic ones. I would suggest that you try to make a set from some 1/8" x 1/2" brass bar stock. You machine off the edge at a 45-degree bevel and then make some flats along it where the set screws go. John D.L. Johnson jjohnsonx~xxLocoGear.com www.LocoGear.com ------- Date: Sun, 13 May 2001 20:00:08 -0700 From: "John Johnson" Subject: Re: Gibs for late model 12 X 36 > > You machine off the edge at a 45-degree bevel and then make some > > flats along it where the set screws go. > Shouldn't that be 30* or 60* (depending on point of view) as the > slides are 60* are they not? Yes, 30-60 is correct. Sorry for any confusion. John D.L. Johnson www.LocoGear.com ------- Date: Tue, 15 May 2001 18:51:06 EDT From: LADDERBARx~xxaol.com Subject: Re: Tumbler Gears On Atlas 12" Lathe [LOOSE NOISY GEARS, WITH WORN CENTRE HOLES] MSC makes a bronze bushing kit (per lubed) that all different sizes. MSC industrial supply 1 -800-645-7270 or WWW.mscdirect.com. It is on page 3619 of the Big Book. part #35375781 SAE-841 oil impregnated bronze bearing assortment. List price is $36.99 this is a 45 piece assortment. Hope it helps. I replaced every bushing in my lathe with it. Anyone with an Atlas should have this kit. Mike ------- Date: Thu, 24 May 2001 17:08:51 +0000 From: Jon Elson Subject: Re: Drive pin slippage on Craftsman 12X24 STYSx~xxMINDSPRING.COM wrote: > I am having a re-occurring problem with my 12X24. I am currently > working on a large diameter (11.5") face plate that I made out of > scrap aluminum. I have all but completed it with the exception of > truing up the face. When I start to make a light cut (approximately > .002 to.005"), the drive pin disengages, and the face plate stops > rotating. Now, this has happened to me a number of times in the past, > but I stop the lathe, push the pin back in, and continue on my merry > way. It usually happens when I try to take a "heavy" cut which for me > is greater than >.010" depth. But tonight I can't go more that 1/4" > worth of travel across the face of the faceplate before it disengages > again. I'm afraid that either the drive pin hole in the spindle > pulley assembly is tapered or the drive pin in the bull gear is > tapered. I should also state that I am not using the backgears. > Any suggestions other then disassembly and inspection? I suspect either the spring, ball, or both have been dropped out of the pin assembly. There are two detent grooves in the pin, and the ball and spring are to hold the pin in those positions. It is also possible that the bull gear is loose or improperly positioned. It is held in place by an angled set screw to the spindle. If it is free to wobble, due to the setscrew being loose, it may act to work the drive pin back from the engaged position. Tapering of the hole and the pin are likely. My detents are pretty strong, however. I can barely pull the pin when I have a little oil on my hands, so the detent must be resisting to the tune of about 50 Lbs. Jon ------- Date: Fri, 25 May 2001 01:50:43 -0000 From: STYSx~xxMINDSPRING.COM Subject: Re: Drive pin slippage on Craftsman 12X24 Jon, after I posted this question, I when back into my shop and finished the face plate in the fastest backgear. It worked fine, but the rpm's were a little slow. After I was done cleaning up, I took a closer looked the spindle assembly with a flashlight. I found that when I pushed in the drive pin, and held the spindle pulley assembly from moving, I could get about 5 degrees of movement between the bull gear and the spindle! I did find that the set screw on the bull gear had backed out, and the bull gear was loose on the spindle. I tighten it, and now the only play is between the drive pin and the bull gear / spindle pulley assembly, and is greatly reduced. I'm pretty sure that the ball & pin are still in place, for there is some resistance when I pull or push on the drive pin. But its a lot less that 50lbs. I bet the combination of a weak spring and the loose bull gear caused my problem. I'll get a chance to turn this week end, and I'll see if the problem has gone away. If not, I guess I'll need to partially disassemble the spindle assembly, and see about replacing that spring... Thanks Rick Stys Apex, NC Craftsman / Atlas 12X24 ------- Date: Thu, 24 May 2001 20:11:58 -0700 From: Jerry Rude Subject: Re: Drive pin slippage on Craftsman 12X24 Rick: Hi, I'm new to the list, but just fixed the same problem on my 10 inch model. What had happened is the large gear allen screw wouldn't hold the gear in place, slipping slightly. This and the fact the back gear pin was loose in its hole, having slipped out so many times. So I reamed the pin hole, and made a new pin, about .015 larger out of a piece of SS. Then, make sure the gear is tight up against the pulley and the allen screw tightened well. If it continues to slip in the future, I'll make a clamp which will hold the gear in place, not allowing it to move laterally. Jerry Rude 10F x 48 newly purchased but still awaiting parts to complete it. ------- Date: Thu, 24 May 2001 23:36:13 -0400 From: Ronald Thibault Subject: Re: Drive pin slippage on Craftsman 12X24 The pin can be removed for inspection. Normally the spring ball assembly prevents the pin from coming out as the pin has shoulders on either side of the ball. To remove mine I carved a little wedge out of a craft stick, and inserted it next to the pulley end shoulder. The ball then rode up the wedge and past the shoulder, releasing the pin. Ron Thibault North Augusta, SC USA Builder Miinie #2 Captain R/C Combat Ship USS Arizona http://pages.prodigy.net/thibaultr/ ------- Date: Tue, 12 Jun 2001 04:19:07 +0000 From: Jon Elson Subject: Re: atlas lathe parting problem brluckx~xxnbnet.nb.ca wrote: > I have a atlas 12" underdrive lathe and have just > purchased a new parting tool . I am new to using this lathe. I have > used a larger standard modern 12" for parting and had no trouble. > Are atlas lathe too light for parting cold rolled and mild steel ? No, but if anything is loose, it won't work well! I had a rather sloppy Atlas 10", but when I tightened up all the gibs it worked much better. There are two steel plates under the carriage that prevent the carriage from lifting up from the bed. Try to lift your bed at the front and back. Observe the oil film right at the edge of the carriage. It will detect movement of .001" or so, even better than you can feel the slack. If there is looseness there, you can remove these plates and remove a lamination from the shim to reduce the slack. I think the laminations are .004", so you may want to put a sheet of kitchen aluminum foil or two back to get halfway in between. Make sure to check at the tailstock end of the lathe, it will bind there if you get it too tight. (The more worn area at the headstock end may show more slack at that point.) > I have the lantern style toolpost. The lathe just wants to chatter > itself to peices. I have tried grinding a edge to make the chips role > but have had no luck . How much should a 3/4 horsepower underdrive 12" > lathe be able to cut ? Any suggestions would be appreciated. It will cut plenty, but only if it's tight. If there is slop anywhere, it will show up worse in the parting-off operation than anywhere else. The infeed force is so high, it can lift the rear of the carriage. But, also, check the compound for slack. You may have to tighten the gibs on the compound for parting-off. The lantern toolpost is a horror. I replaced mine over 10 years ago with a Phase-II knockoff of the Aloris-style dovetail toolpost, and it made an enormous difference on a 10" Atlas. I've upgraded to a 12" Atlas, and I still use that toolpost, and highly recommend it. Finally, don't forget the spindle and chuck. If you have a dial indicator, check the spindle for free play (both axial and radial). Apply a 50 Lb force upward as close to the chuck or spindle nose as possible. If there is more than a few thousandths of free play, you need to inspect further. If this is a babbit bearing lathe, there are shims under the bearing caps that can be removed, but free play indicates wear, and when you pull shims the bearing will no longer be round. If this is a Timken roller bearing lathe, then your bearings may be worn out, or the preload may need to be adjusted. Finally, the chuck jaws need to grip a bar along the full length of the jaw. A common problem is known as "bellmouthing", where the outermost part of the jaws are worn, so only the back of the jaw actually grips the work. If you can wiggle the bar in the jaws when the chuck is just very lightly tightened on the work, that is an indication. There are several procedures for grinding the jaws on the lathe, so they are aligned with the lathe's axis. A Dremel tool, air grinder or other spindle can be fixed to the toolpost to do this. It takes only a few minutes and makes a huge difference in all tougher turning jobs. Then, there is technique, but you probably know this. But, it is counter-intuitive that you need to keep the feed up when it starts to chatter, although your instinct is to slow down. I still have some trouble parting off aluminum pieces sometimes, but steel parts off silently and almost effortlessly on my 12" Atlas. I had enormous problems (all of the ones mentioned above, and then some) with my original 10" Atlas, and corrected them over time, as I figured out what was wrong with it. Hope some of this helps! Jon ------- From: johnt49x~xxh... Date: Wed Jul 25, 2001 11:07 am Subject: Re: 618 101.21400 Spindle removal?? > Hello to all (Ultimate newbie here), I need to remove the spindle, I > have read the Atlas's online bulletin on how to do this, and one part > that is not comprehensible: > "Place the piece of broomstick at the left end of spindle S and drive > in direction indicated by arrow until > key T emerges from gear R." > Fine. But how does one "drive" it? They warn about not "hammering with > a metal hammer" and this can't be done by hand. Any advise please? Alex Alex, I recently replaced my spindle bearings. It's ok to use a metal hammer to hit the broomstick, just don't hit the spindle directly. I used a piece of 2x2 & a ball peen hammer. I'd advise threading the collar back on the spindle flush with the spindle end after removing gear & spacer to protect the threads. Be sure you loosen set screw on collar that locates spindle pulley first. It took several good "taps" to get spindle moving, this may damage bearings, but you have little choice. Probably a good idea to replace them any way while it's apart. Two new bearings & cups came to a grand total of $22.96. Don't even consider buying these from Clausing. They want $45.80 ea! Any good bearing supply should have, or be able to get them for you. Timken P/N - 07079 Left bearing (1) - 07100 Right bearing (1) - 07196 bearing cups (2) When you reasssemble be careful when thighening collar on spindle end. If you tighten bearings too much you will have to "tap" spindle to loosen again as bearings are a press fit. You want just a slight amount of pre load on bearings. This is also a good time to replace your belt as you will probably never need to remove spindle again unless something breaks. Good luck, John ------- From: "Bob May" Date: Wed Jul 25, 2001 1:38 pm Subject: Re: [atlas_craftsman] 618 101.21400 Spindle removal?? What kills the bearings with a direct blow with a hammer is the very high force that gets generated when the hammer strikes. "Dead Blow" hammers use a cushion so that the peak force (which can easily deform steel) is lessened and spread over a longer time interval. The total inertia transfer is usually about the same but it's spread over a longer time and thus, the deformation pressures aren't attained anywhere along the line. I might also note that when you do use a dead blow hammer, you insure that the slack is taken up in all of the moving parts or you will just have the bearing slam against the far side and thus get the same high deformation pressures develop. This problem is why you usually see things like the broomstick method used as you will naturally push the stick down to the work and that takes up the slack so that you don't get the sudden shock of the impact of the internal parts. Bob May http://nav.to/bobmay ------- From: HUNLEY31x~xxa... Date: Wed Jul 25, 2001 4:18 pm Subject: Re: [atlas_craftsman] 618 101.21400 Spindle removal?? Alex, I just removed mine (101.07403) and had a hard time with it. After two hours I applied a little heat on the bearing (NOT HOT), that did the trick. I wasn't sure, thought I was doing something wrong, as it was so hard to 'break loose' but it came with a lot of effort. I agree with what everybody else stated. If I can add anything, it would be to screw the end collar back on before you start beating on the shaft. If for no other reason than to 'correct' any of the end threads when you remove the collar that may be damaged when 'tapping on the shaft.' Of course you must remove the collar to complete the removal, but I saw it as some insurance I could correct the end damaged threads if needed. As it was the machine weathered the experience better than I. It didn't shed a drop of blood. LOL. You want to be real careful, don't do anything you're not sure of, just look at the replacement prices of the 'stuff' you're beating on. Regards, Hank ------- From: catboat15x~xxa... Date: Wed Jul 25, 2001 8:35 pm Subject: Re: [atlas_craftsman] 618 101.21400 Spindle removal?? In a message dated 7/25/01, cravdraax~xxy... writes: > Fine. But how does one "drive" it? They warn about not "hammering with > a metal hammer" and this can't be done by hand. If you can't get hold of a lead, bronze, wood hammer go ahead with your household nail hammer, but put a chunk of wood that will take the sharp blow and distribute the force over the end you are driving. John Meacham High Desert of California, Palmdale, Littlerock. ------- From: sleykinx~xxa... Date: Wed Jul 25, 2001 8:44 pm Subject: Re: [atlas_craftsman] Re: 618 101.21400 Spindle removal?? johnt49x~xxh... writes: > When you reasssemble be careful when thighening collar on spindle end. > If you tighten bearings too much you will have to "tap" spindle to > loosen again as bearings are a press fit. You want just a slight > amount of pre load on bearings. One more point .. Make sure you put something soft (shotgun pellet, bit of brass or?) under the setscrew in the preload collar so the threads don't get munged. Glenn Neff Medford, OR ------- From: S1 Date: Thu Jul 26, 2001 5:41 am Subject: Re: [atlas_craftsman] 618 101.21400 Spindle removal?? It seems this would works well also. Something that would help the process is stuffing some dry ice inside the spindle to shrink it some, while lightly heating the bearings. The bearings expand, while the the spindle shrinks. A friend of mine buried a piece of 6" solid round bar in dry ice and its diameter shrunk .100". -Gabe ------- From: "Larry Bailey" Date: Thu Aug 16, 2001 1:53 pm Subject: Re: [atlas_craftsman] Re: Rollie's Dad's Lathe Alignment Question >sleykinx~xxa... wrote: > > In a message dated 08/16/2001,skip_evans writes: > > > I would adjust the tailstock to read zero. Right now you would > > > produce a slight taper. >From: Jon Elson >Then it is almost hopeless. Unless you have a bar that is both VERY >stiff, and very light, it is pretty hard to get it to stay straight. >A 1" steel bar hanging even one foot out of the chuck will droop a bit, >and deflect away when you touch it with the indicator. Using a level, >I can measure the bed twist right up against the headstock, and at the >rightmost end of the bed, however long the bed may be. that is a much >more accurate way of removing twist than trying to measure a bar in the >chuck. If you can come up with a 1 or 1.5" OD hollow roller that has >been centerless ground, that would make a much better test bar for >this purpose. It's been a while since I read through this method. I tried it once and found it rather cumbersome. IIRC the bar doesn't need to be perfectly straight or without taper but does to be measured accurately. Its location has to be measured accurately as well. So a reasonably straight, smooth bar, a dial indicator and a micrometer are the things you need. I tend to agree with Jon. I put a level on mine, tweak the mounting bolts and turn a test bar. The first time I did this I couldn't see a difference on the mic six inches from the chuck. Now if I need to relevel I often don't even bother with a test bar. Larry ------- From: rweersingx~xxw... Date: Fri Aug 17, 2001 4:38 am Subject: Re: Serial Number Location In atlas_craftsman, Robert McDonald wrote: > Thanks Bob. I guess mine is a 10F then, as I have the separate > apron, 3/4" lead screw, and power cross feed. > How did you determine what year yours were made? Rob Hello Rob, on the old lathes, Atlas would Date the spindle bearings with the day month and year. All bets are off if the bearings were replaced but since my lathes had such old dates I assumed that they were the original. I was surprised that my newer model "f" had an older date than my "D" model. I have since found out that Atlas made the "d" model until 1941. The "D" model I inherited from my grandfather when I was a child. My grandfather got the lathe out of the trash behind a machine shop in Kalamazoo Michigan about 1950 and I think he rebuilt it because many of the parts look new. I have a 1950 parts list and it is unbelieveable how cheap things were back then. I ramble on, good luck Bob ------- Date: Sun, 19 Aug 2001 20:46:46 -0400 From: "Ebower" Subject: Re: Re: I have plans for 6" New Style QC box.. There was one issue "Projects in Metal" August 1989. Should get October 1989 issue due to some corrections/omissions in above issue. The guy that did the original plans "John Toscano" was the writer. The second Magazine is "Modeltec" Six parts. George W. Yadon was the writer. July, August, September, October, November, and December 1991. This is a copy of John's but made from plate. Total plans in the article. The third Magazine is also "Projects in Metal" December 1992 Glenn A. Pettit. This is a different version of the gear box. Total plans in the article. Earl ------- Date: Fri, 24 Aug 2001 11:12:32 -0700 From: "Bob May" Subject: Re: Taper Turning Actually, it isn't that the bed needs to be level but rather that it's not twisted. A twisted bed will produce a taper but a bed that is tilted at 45 deg. and not twisted will not produce that taper. Making the bed level is the simplest way tho of making an attempt at insuring that the bed isn't twisted. I'd check your calculations and settings on the lathe to insure that the taper is correct. I'd also try doing a 0deg. taper (a cylinder) as a reference guidepoint. Bob May http://nav.to/bobmay ------ Date: Fri, 24 Aug 2001 18:18:23 +0000 From: Jon Elson Subject: Re: Taper Turning >> Thanks for the reply. I have the Starrett level you describe. I took the lathe off of the stand and leveled the stand and then put the lathe back on and leveled it. It still is 3 degrees off. Any other suggestions would be appreciated. EA << No, leveling the stand is meaningless. You need to level the BED ways of the lathe, to get both ends parallel. I use a master precision level which brings them to a couple of arc seconds of level. these levels will EASILY detect a hair under one end! But, I doubt that this is your problem. To get a 3 degree error, you'd need a visible twist in the bed. What you need to do is get a large piece of material, and try to face it flat in the chuck, using the compound to move the tool. When you get it so it is flat, and not a convex or concave cone, then, you can scribe the 90 degree mark. Using the compound to cut a cylinder of constant diameter, you can check the mark and make sure it lines up with the zero on the cross slide. If they don't match, then you have some kind of foul up with the markings. If they line up, all other marks should line up, too. For precise tapers, you need to have a master of known correct taper, and fit the master into/onto the part you are making, using bluing dye to check for the accuracy of the fit. When the bluing is transferred for the full length of the taper, then you know that your part correctly duplicates the taper of the master. One thing to beware of on old lathes is that the compound can be worn unevenly, causing it to travel in a curved path. You can't cut any taper with accuracy when the compound is in that kind of shape! Jon ------- Date: Fri, 24 Aug 2001 20:47:35 -0000 From: doogdoogx~xxhawaii.rr.com Subject: Re: Taper Turning In atlas_craftsman, ejohna wrote: > If I set the rest for a 30 degree taper I end up with a 33 degree. I > find that if I set the rest to 0 degrees it is not square with the > chuck. I have to set it a 3 degrees to get it square. Is there an > adjustment to correct this or should I rescibe the line on the rest? Aloha, after doing what all of the other replies suggest I would if possible turn it using the tailstock center to keep it from deflecting and use a sharp bit. Check to see if your gibs are snug and not sloppy. Some of the Atlas, Craftsman use a nylon type of gib and after a while it cracks and creates a loose spot so be sure to check what type of gib you have. I doubt that the markings on the cross slide and compound could be 3 deg's off but it is possible. Hope this helps. Mahalo, Howard ------- Date: Fri, 24 Aug 2001 17:31:43 -0700 From: Frank Evan Perdicaro Subject: Taper issue Your problem could be as simple as the problem on my 10F. Totally worn out everything! Even after I replaced both precision nuts in the compound (one for each screw) I can still move the bit back and forth with my hand, but not an eight of an inch, like before. (No exaggeration there, really that much.) It appears I need to replace all three screws on my lathe too. Most of you would flat-out not believe how worn my lathe is. The screwforms are no longer Acme, or even a typical 60 degree thread form, but a sort of truncated 60 degree thread form. The nuts that engaged the screws were only slightly different than cylinders. ------- Date: Fri, 24 Aug 2001 21:06:20 -0400 From: "EA" Subject: Re: Taper Turning Thanks for the reply.If I install the face plate and take the tool post off, set the rest at 0 degrees and use a good square from the slot for the tool post to the face plate should that be square? This is a new lathe, less that 25 hours. After I leveled the stand then I did level the bed with a Starrett precision level. Both ways are level from the head to the tail and also from one way to the other at both the head & tail. ------- Date: Sat, 25 Aug 2001 06:21:32 +0000 From: Jon Elson Subject: Re: Taper Turning >Thanks for the reply.If I install the face plate and take the tool >post off, set the rest at 0 degrees and use a good square from the >slot for the tool post to the face plate should that be square? EA You need to turn the faceplate to make sure it is truly flat and square to the spindle axis. (Nothing can be trusted until you've checked it!) By turn, I mean using a dial indicator, as we already know there is a problem in the lathe. If the faceplate is running pretty true, then you should verify that the cross slide travels parallel to the faceplate. If the cross slide IS parallel, then you can check the degree marks for the compound, and see if they need adjusting. If the cross slide is not at right angles to the spindle axis, then don't even look at the degree marks, as the problem is below them. ------- Date: Sat, 25 Aug 2001 06:14:42 -0000 From: rweersingx~xxworldnet.att.net Subject: Re: Taper Turning I would check the gibs and if they are Ok I would rescribe the line. I have had to do this with a number of machines and accessories. They probably scribed the line at the factory before the rest was mounted on the machine. Good luck Bob 618 Atlas lathe 10X36 F Atlas lathe(1939) 10X42 D Atlas lathe (1940) U.S. Burk Millrite milling machine (1968) ------- Date: Sat, 25 Aug 2001 04:07:03 -0400 From: "Matthew King" Subject: Re: Best collet choice? + lathe work question [SNIP: COLLET PORTION IS IN "Atlas Collets" FILE] A question for you lathe veterans - I have a Harrison 12x40 lathe that I cannot get a quality finish with, regardless of carbide insert used, HSS toolbit, cemented carbide, rusty nail, etc. (just kidding about the nail!) I've leveled the bed with a Starret machinist's level(80-90 seconds or .005" per foot - not quite a "master precision level (10 second or .0005" per foot) but not $500 either!) I've got an Aloris CXA toolpost. I've meticulously followed the recommended speed and feed charts for all materials cut. The only acceptable finish I've been able to get is in some Nylon, but you can still see "waves". Stainless steel (I know it's contrary but this is AWFUL) is horrendous. It looks "ripped." Carbon steel of various hardness is a bit better, but certainly not acceptable, even at the slowest possible feed rates. Aluminum is relatively smooth but still wavy. I don't believe there's any taper being introduced, just an AWFUL finish. I've tried very large nose radius inserts, very narrow radius inserts, 1/2" wide square cemented toolbits, carefully ground (by an ex-Pratt & Whitney machinist friend) HSS toolbits. We're at a complete loss here. The machine was built in 66 with a period 3phase 3HP dual speed motor that appears quite smooth running. The gear- case is run by dual V-belts that are properly tensioned. All of the visible gears appear in quite good shape and are properly lubed. The gearcase itself is a submerged bath (Mobil Heavy Vactra) system properly filled. The spindle bearing "play" is <.002" from one extreme to the other (using the pipe in chuck, indicator on chuck, lift and shove method). Material can be centered within .0005-.001" in the Pratt three jaw chuck. A dial indicator traversed across a 1 foot piece of material shows ZERO runout from chuck towards tailstock. A slightly notchy live center has been being used and is being replaced just in case, but can't possibly impart this level of roughness. It's just as bad when turning without the tailstock in place. HELP! PLEASE! Any ideas? Thanks, Matt King Columbus, GA no Atlas(yet), but a Harrison! ------- Date: Tue, 28 Aug 2001 18:04:25 -0000 From: rweersingx~xxworldnet.att.net Subject: Re: Best collet choice? + lathe [HARRISON] work question Hello Matt, I had the same problem with a 6" Atlas lathe. I replaced the crossfeed nut and snugged up all the gibs which helped, but I was still getting a rough finish. About a month later I took the spindle of to replace the belt and noticed the preload on the bearings seemed too loose. Putting the spindle back together with the proper preload on the bearings cured all of the rough finish problems. Hope that helps since you seem to have done everything else. Good luck Bob ------- Date: Sun, 26 Aug 2001 00:35:58 EDT From: CaptonZapx~xxaol.com Subject: The Color Photo Lathe I have a unique lathe that has me intrigued. It is an Atlas head stock and bed, with two carriages with cross slides, no compounds, a lead screw that has a blank section in the center of it, and a rudimentary set of gears to drive the lead screw. It was used for cutting rotogravure plates for printing. The bed is like new, and the cross slides do not show any wear. I assume that once you set the depth of cut, the only motion was along the bed, with the lead screw moving both carriages in unison, the photo pick up looking at the object photo, and the vibrating head cutter doing the engraving. It didn't get much use, judging by the absence of wear marks on the bed. Needless to say, the thing looks like a brand new lathe to me, just short some critical parts. Has anyone seen one like it? And does anybody know where I could find parts for it to turn it into a proper lathe. The most critical part would be a QC gear box and lead screw. A tail stock would be nice, although I have a tail stock off of a Grizzley that could be made to work. Thanks for any help, Jerry Roy ------- Date: Sat, 25 Aug 2001 23:33:04 -0500 From: "M K (Skip)Campbell Jr." Subject: Re: The Color Photo Lathe Jerry, I bought one just like it to upgrade my 101.28990. It is the identical lathe except for the oddessy's you mention. It perfect for upgrading or renewing I should say, the 101.28990 or 28991 or any late model Craftsman/Atlas lathe. I took the quick change and drive gears, lead screw and tail stock, motor and pulleys off my lathe and put them on the photo lathe. I later found a like new lead screw and replaced the well worn one on my lathe (which I still have). My lathe is now in great shape. Skip Campbell ------- Date: Sun, 26 Aug 2001 07:24:06 -0000 From: nathanandannax~xxcs.com Subject: Half Nuts First off, thanks to all who responded to my post on varying thread pitch. I was trying another thread today when I noticed that the half nuts open and close slightly as the carriage oves along. I pulled the carriage off and the half nuts are loose in the bracket that they slide in. When I say loose, I mean at least .030 side to side and up and down. They do not appear to be worn much so I am not sure if this is normal or if I am missing a shim or something. The lathe was a basket case when I got it so it could be missing something. It seems plausible that this could be why I am having inconsistencies with my threads. Thanks again for all the help, Nathan ------- Date: Sun, 26 Aug 2001 09:06:07 -0500 From: "jerdal" Subject: Re: Half Nuts Again, are you sure the leadscrew is straight? also: The pins that close the halfnuts may be loose in the backsides of the nuts, The pins may be worn or wrong size ("an earlier user's "fix"?) the halfnut carrier block may be worn, letting halfnuts tilt etc the rotating plate that the pins ride in may be worn, The rotating plate may be loose on the engagement lever shaft the engagement lever may be not moving far enough (jammed, blocked) The halfnuts may be worn, but so evenly that you don't see it. You may have to try them on the screw separately after disassembly. Also: try closing them with your fingers after the engagement lever has moved as far as it can, then try to move the carriage back and forth. Is it still loose? do they act like they want to spring apart? I have a logan that had very worn halfnuts, and a very loose carrier. I had 1/8 inch total movement, but I could cut a 32 pitch thread OK, as long as I made sure that the carriage was against the screw, by holding it back after engaging the nuts. That took up the backlash. Try it??? That's all that spewed forth from the old brain right now. Jerry ------- Date: Tue, 28 Aug 2001 18:13:29 -0000 From: sevenish1x~xxyahoo.com Subject: Why does my 12 X 36 chatter? I am new to this group but have many years of machine experience so I am puzzled by a problem I have with my Atlas lathe. I have a primo 12 X 36 that I have extensively refurbished. New belts,headstock bearings, cleaned, oiled, tightened and painted. Looks like new and cuts like crap. I simply cannot get a decent cut no matter what speed, feed, or depth of cut. I have put a dial indicator everywhere and measured for spindle deflection, chuck deflection,tool deflection, barometric pressure and phase of the moon and just I cannot figure out why it cuts so lame. I am using an Aloris type tool holder and have tried both small radius carbide tools and HSS to no avail. The machine always produces a chattered finish except on the very lightest of cuts. Even with the gibs tightened to the max it chatters. Do you folks have any suggestions for what to try? I have operated many lathes over the years but this one has me stumped. I know other people seem to like this machine but at the moment I can't figure out why. Randy Howard ------- Date: Tue, 28 Aug 2001 22:06:22 -0000 From: doogdoogx~xxhawaii.rr.com Subject: Re: Why does my 12 X 36 chatter? Aloha, I would check the following: 1) If you have the horizontal counter shaft type, check to see if the bolt between the horizontal counter shaft and lathe is adj. properly. 2) Is your lathe bolted down or is it just sitting on the bench. I would bolt it to the bench and bolt the bench to the floor. 3) Do you have the metal gibs or the nylon one. If nylon, I would remove the and check to see if it is cracked or broken. 4) Try moving the carriage by hand while turning a round stock and see if the finish is the same or better. If it is better then that will mostly rule out the compound and carriage. 5) Is your lead screw ok? 6) Check your half-nuts for damage and excessive wear and also the assembly that it attaches to. 7) Check your belt to see that it is not too hard. Sometimes when the lathe is sitting a long time with tension on the belt it takes the form of the pulley and it could cause a little vibration. Hint, release the tension lever when lathe is not in use. Hope this helps, and with the other suggestions that were posted you should find the problem cause. Mahalo, Howard ------- Date: Tue, 28 Aug 2001 18:25:53 -0500 From: "Koepke, Kevin" Subject: RE: Re: Why does my 12 X 36 chatter? 36 inch is a long bed for the Atlas bed design. Some, including me think it's too long. I have a 618, and have just recently purchased a 10-F x 24. I have some problems with chatter, but with limitations, I am quite pleased with them. Howard's #2 is most likely to be the problem. The more mass it's bolted to, the better. How about a concrete foundation? ------- Date: Tue, 28 Aug 2001 20:39:48 -0500 From: "jerdal" Subject: Re: Re: Why does my 12 X 36 chatter? Some 110V motors have a devilish vibration which a light lathe (or a heavier one) can transmit to the cutting edge. tends not to change much with turning speed. Might not be your problem if light cuts work OK, but worth a try. Also, there's lots of gibs and other things as well. As you know, if the compound is somehow loose on its little seat, problems occur. Easy to overlook when thinking of gibs. Might be a chip in there? Jerry ------- Date: Wed, 29 Aug 2001 04:12:05 +0000 From: Jon Elson Subject: Re: Why does my 12 X 36 chatter? sevenish1x~xxyahoo.com wrote: > I am new to this group but have many years of machine experience so I > am puzzled by a problem I have with my Atlas lathe. I have a primo > 12 X 36 that I have extensively refurbished. New belts,headstock > bearings, cleaned, oiled, tightened and painted. Looks like new and > cuts like crap. I simply cannot get a decent cut no matter what > speed, feed, or depth of cut. I have put a dial indicator everywhere > and measured for spindle deflection, chuck deflection,tool > deflection, barometric pressure and phase of the moon and just I > cannot figure out why it cuts so lame. I am using an Aloris type tool > holder and have tried both small radius carbide tools and HSS to no > avail. The machine always produces a chattered finish except on the > very lightest of cuts. Even with the gibs tightened to the max it > chatters. Do you folks have any suggestions for what to try? I have > operated many lathes over the years but this one has me stumped. > I know other people seem to like this machine but at the moment I > can't figure out why. Well, I did have chatter problems with my 10" when I got it, but it was a wreck. I now have a 12", and although I can MAKE it chatter, it rarely does, and takes pretty decent cuts. There is something WRONG with your machine. Don't think it is just because all Atlas machines are junk, or something like that. It CAN be cured, and will do a good job after the problem is detected. I assume this is a Timken bearing machine. The one thing you CAN'T do with abandon on lighter machines is take cuts with a WIDE cutting tool (ie. producing a wide chip). That seems to excite the flex in the machine more than anything. I think this is due to flex in the carriage/ compount mounting, which is pretty much the weak link in the Atlas. The Aloris-type toolholder was a great improvement on my 10" Atlas. If you had a lantern-style toolpost, that would have been the first change I would have suggested, but you've already done it. What material are you trying to cut? Some totally unknown scrap from around the shop? That can be the problem. Try some mild steel or aluminum alloy first. Keep the speed high (120 FPM for steel, 500 FPM for aluminum is a good place to start) and the infeed pressure moderate. Make sure the cutting tool is level with the center of the spindle. Make sure the flank of the tool is not rubbing on the work. This can happen if not enough front or side relief has been put on the cutter. Don't try to cut too far from the chuck without supporting the work with a tailstock center. One other problem that I had was 'bellmouthing' of the chuck jaws. When short pieces are gripped in the jaws a lot, the tips of the jaws suffer more. wear, and the jaws will only grip long pieces in the back of the chuck. With the chuck slightly snugged up, see if you can wiggle a rod in the chuck. If so, the jaw tips are not gripping the work. This will make easy work very difficult and frustrating. The fix is to use whatever grinding equipment you can come up with to get a small grinding wheel inside the chuck. You need a wheel that will fit inside the hole in the chuck, so you can grind the jaws all the way back. What you do is install the Dremel, air die grinder, toolpost grinder, electric drill or whatever you've got to the toolpost, at approximately the center height of the spindle. Use chewing gum, rubber bands, putty, or whatever to pull the chuck jaws outward, so they ride the same side of the scroll as when they are gripping a bar. Adjust the jaws so they are somewhat smaller than the center hole. Set the chuck turning very slowly, with the feed screw running on a fine feed setting. Advance the grinding wheel into the chuck with the carriage carefully, and then bring the grinder out with the crossfeed until the wheel just touches the jaws. Engage the power feed, and let the grinder slowly work inward. If the bellmouthing is severe, you may have to start at the back (where there's more metal) and work outwards. I actually do this with the chuck stopped, and make the preliminary roughing passes manually, until the jaws are pretty much trued up, then finish with one power-fed pass.This saves time, as the wheel hardly ever touches the jaws when the chuck is turning - you're mostly cutting air. You'd be amazed at what a difference a set of trued-up jaws will make on a worn lathe chuck. It is a good idea to cover the ways with aluminum foil, rags, paper towels or whatever, to keep the grinding grit out of the carriage. A couple places to look on the Atlas lathe for looseness are the swivel joint where the compound sits on the cross slide, and the gibs hidden on the underside of the carriage. These really shouldn't be a problem for normal cutting, but can cause major crashes when using cutoff tools or heavy threading in steel. You can check them by trying to lift straight up on the front and rear of the carriage.It should be constrained to within .001" or so. One last possibility (you say you've already checked) is looseness of the chuck mounting at the spindle thread. A poorly-cut thread could be loose enough to allow the chuck to wobble under cutting forces. One way to check is to loosen the chuck from the spindle about 1/4 turn, and try to rock it on the thread. A little looseness is normal, but if it really rocks a lot, then the thread may be too loose. it might only allow the chuck to shift under cutting loads, and so a manual test with a dial indicator might not show the problem. The test I use is to put a one foot bar (1 " or more diameter) in the chuck, and put a dial indicator on the back of the chuck body. Lift up with about 50 lbs force at the end of the bar. The chuck body should not rise up by more than .001". Now, you have to take some care in how you mount the dial indicator, or you will measure bed flex rather than spindle stiffness with this. So, mounting the dial indicator on the compound would be misleading. You want to mount it to the headstock casting if possible, otherwise to the bed as close to the headstock as possible. There is a fairly elaborate bearing preload scheme, which requires running the lathe at high speed for 8 hours to heat the spindle, and then the bearing preload is set. I do it by observing the above mentioned measurement and increasing preload in small increments until the spindle is well constrained. That seems to work fine. Jon ------- Date: Wed, 29 Aug 2001 16:04:10 -0000 From: gppainex~xxtir.com Subject: Re: Why does my 12 X 36 chatter? John provided a lot of good information, and it is likely that checking the chuck to spindle play will pick up these conditions, but I'd like to point to a couple more areas I've seen cause chatter trouble in a friend's 12 x 36. One was the bolts holding the headstock to the bed were not tight and would allow the headstock to move under load. The other was loose screws that hold the chuck together that let the front half of the chuck move with respect to the backplate. Can't say how all that got loose, but snugging things up made a major improvement in quality of cut. Good luck, Gary ------- Date: Wed, 29 Aug 2001 16:58:23 +0000 From: Jon Elson Subject: Re: Re: Why does my 12 X 36 chatter? > I'd like to point to a couple more areas I've seen cause chatter > trouble in a friend's 12 x 36. One was the bolts holding the > headstock to the bed were not tight and would allow the headstock to > move under load. The other was loose screws that hold the chuck > together that let the front half of the chuck move with respect to the > backplate. Can't say how all that got loose, but snugging things up > made a major improvement in quality of cut. Either of these two conditions can also be caused by little bits of grit, paint flakes, etc. that get between finely machined surfaces that need to fit precisely. Jon ------ Date: Wed, 29 Aug 2001 16:36:25 From: "robert B" Subject: Re: Why does my 12 X 36 chatter? I'm by far not the expert here, but I've had problems with chatter to. Mostly when turning between centers, with the chatter marks on the headstock end. All I could take were very light cuts. Problem was, a belt was slipping. ------- Date: Wed, 29 Aug 2001 10:34:10 -0700 From: Frank Evan Perdicaro Subject: Re: Why does my 12 X 36 chatter? Having replaced lots of parts on my 10F, I still get chatter. On my lathe, one of the culprits is the compound screw mount. Not the nut, and not the threaded part of the compound screw, but the part nearest the handle. If the mount is worn, the top-most part of the compound can move even if there is zero backlash on the screw. Solution? New compound screw assembly. Has anybody ever tried adding mass to the bed? It seems to me one could disassemble the lathe, turn it upside down and fill the underside with a mix of castable urethane and lead shot. First clean everything, then lay in a piece of 1/2" styrofoam. Then mix up the lead/urethane mix and fill the inverted bed right up. When the mix is set, flip it back over and remove the styrofoam with a gasoline rinse. The gap between the top of the filler and bottom of the bed should be enough to let the tailstock operate correctly. This mix would kill chatter and would probably weigh 100 lbs. [NOTE: BAGS OF SAND STRATEGICALLY PLACED ON THE LATHE STAND WILL DO WONDERS -- CHEAPLY.] ------- Date: Thu, 30 Aug 2001 13:47:23 -0700 From: "GuyW" Subject: Re: Re: ...chatter? LONG Hi group...since I've been collecting info on chatter (as result of my interest in building the Gingery lathe, among other reasons), so I'll post it here SOME IDEAS ON SOURCES OF AND SOLUTIONS TO, LATHE